TWI880893B - n-type GaN crystal, GaN wafer, and method for manufacturing GaN crystal, GaN wafer and nitride semiconductor device - Google Patents

Abstract

Translated fromChinese

可與以氨熱法成長之GaN結晶匹敵的、具有20 arcsec以下之（004）XRD搖擺曲線FWHM的GaN結晶，若能夠以量產性優良的HVPE使其成長，則可期待促進開發使用c面GaN晶圓作為基板而生產的氮化物半導體裝置以及對於低成本化有所貢獻。本發明之n型GaN結晶，其所含有之最高濃度的施體雜質為Ge，具有小於0.03 Ω･cm的室溫電阻率，其（004）XRD搖擺曲線FWHM小於20 arcsec。該n型GaN結晶，具有面積分別在3 cm²以上的2個主面，其中一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下。再者，該n型GaN結晶可具有20 mm以上的直徑。If a GaN crystal having a (004) XRD swing curve FWHM of less than 20 arcsec, which is comparable to a GaN crystal grown by an ammonothermal method, can be grown by HVPE with excellent mass productivity, it is expected to promote the development of nitride semiconductor devices produced using c-plane GaN wafers as substrates and contribute to cost reduction. The n-type GaN crystal of the present invention contains Ge as the highest concentration of donor impurities, has a room temperature resistivity of less than 0.03 Ω･cm, and a (004) XRD swing curve FWHM of less than 20 arcsec. The n-type GaN crystal has two main surfaces each having an area of more than 3^cm2 , one of which is Ga-polar and has an inclination of more than 0 degrees and less than 10 degrees relative to a (0001) crystal plane. The n-type GaN crystal may have a diameter of more than 20 mm.

Description

Translated fromChinese

n型GaN結晶、GaN晶圓、及GaN結晶、GaN晶圓及氮化物半導體裝置的製造方法n-type GaN crystal, GaN wafer, and manufacturing method of GaN crystal, GaN wafer and nitride semiconductor device

本發明主要係關於n型GaN結晶、GaN晶圓、及GaN結晶、GaN晶圓及氮化物半導體裝置的製造方法。The present invention mainly relates to n-type GaN crystal, GaN wafer, and manufacturing methods of GaN crystal, GaN wafer and nitride semiconductor device.

GaN（氮化鎵）為III-V族化合物半導體的一種，具備屬於六方晶系的纖鋅礦型的結晶構造。塊體GaN結晶的代表性成長技法中，具有氫化物氣相磊晶（HVPE，Hydride Vapor Phase Epitaxy）、高壓溶液成長法、氨熱法及Na助熔劑法（非專利文獻1）。HVPE相較於其他技法，GaN結晶的成長速率特別高，目前市售的GaN晶圓幾乎皆是以HVPE進行成長。GaN (gallium nitride) is a type of III-V compound semiconductor with a hexagonal crystalline structure of fibrous zincite.The representative growth techniques for bulk GaN crystals include hydride vapor phase epitaxy (HVPE), high pressure solution growth method, ammonothermal method and Na flux method (non-patent document 1). Compared with other techniques, HVPE has a particularly high growth rate for GaN crystals. Almost all GaN wafers currently on the market are grown using HVPE.

有報告提出在以氨熱法成長的直徑1英吋的c面GaN晶種晶圓上，以HVPE使GaN結晶成長，再從該GaN結晶裁切出直徑18 mm的c面GaN晶圓（非專利文獻2）。有報告提出在以氨熱法成長的c面GaN晶種晶圓上，以HVPE使GaN結晶成長，再從該經過HVPE成長的GaN結晶裁切出c面晶種晶圓，然後藉由HVPE於其上使摻雜了Si（矽）的GaN結晶成長（非專利文獻3）。其中指出該摻雜了Si的GaN結晶的（002）XRD搖擺曲線FWHM為32 arcsec。有報告提出在以氨熱法成長的c面GaN晶種晶圓上，藉由HVPE使摻雜了Ge（鍺）的GaN結晶成長（非專利文獻4）。其中指出該摻雜了Ge的GaN結晶的（002）XRD搖擺曲線FWHM為67 arcsec。A report proposes to grow GaN crystals by HVPE on a 1-inch diameter c-plane GaN seed wafer grown by ammonothermal method, and then cut a c-plane GaN wafer with a diameter of 18 mm from the GaN crystal (non-patent document 2).A report proposes to grow GaN crystals by HVPE on a c-plane GaN seed wafer grown by ammonothermal method, and then cut a c-plane seed wafer from the GaN crystal grown by HVPE, and then grow Si (silicon) doped GaN crystals thereon by HVPE (non-patent document 3). It is pointed out that the (002) XRD swing curve FWHM of the GaN crystal doped with Si is 32 arcsec.There is a report that Ge-doped GaN crystals were grown on c-plane GaN seed wafers grown by ammonothermal method by HVPE (Non-patent document 4). It is pointed out that the FWHM of the (002) XRD swing curve of the Ge-doped GaN crystals is 67 arcsec.

有報告提出在以酸性氨熱法成長的m面GaN晶種晶圓上，以HVPE使厚度5.6 mm的GaN結晶成長，而從該經過HVPE成長的GaN結晶裁切出直徑2英吋的m面GaN晶圓（非專利文獻5）。在該2英吋HVPE晶圓的中央，得到13 arcsec這樣的（200）XRD搖擺曲線FWHM。已知一種導電性c面GaN晶圓，其係使用NH₄F（氟化銨）與NH₄I（碘化銨）作為礦化劑而以酸性氨熱法進行成長的GaN結晶所構成，而（004）XRD搖擺曲線FWHM約為 10arcsec（專利文獻1）。上述提出的XRD為X射線繞射（X-Ray Diffraction）、FWHM為半高全寬（Full Width at Half Maximum）。[先前技術文獻][專利文獻]There is a report that GaN crystals with a thickness of 5.6 mm were grown on m-plane GaN seed wafers grown by acidic ammonothermal method by HVPE, and m-plane GaN wafers with a diameter of 2 inches were cut from the GaN crystals grown by HVPE (Non-patent document 5). At the center of the 2-inch HVPE wafer, a (200) XRD swing curve FWHM of 13 arcsec was obtained. A conductive c-plane GaN wafer is known, which is composed of GaN crystals grown by acidic ammonothermal method using NH₄ F (ammonium fluoride) and NH₄ I (ammonium iodide) as mineralizing agents, and the (004) XRD swing curve FWHM is about 10 arcsec (Patent document 1). The XRD mentioned above is X-ray Diffraction, and FWHM is Full Width at Half Maximum. [Prior Technical Literature] [Patent Literature]

[專利文獻1]WO2018/030311A1[非專利文獻][Patent document 1] WO2018/030311A1[Non-patent document]

[非專利文獻1]H. Amano, Japanese Journal of Applied Physics 52 (2013) 050001[非專利文獻2]J. Z. Domagala, et al., Journal of Crystal Growth 456 (2016) 80[非專利文獻3]M. Iwinska, et al., Journal of Crystal Growth 456 (2016) 91[非專利文獻4]M. Iwinska, et al., Journal of Crystal Growth 480 (2017) 102[非專利文獻5]Y. Tsukada, et al., Japanese Journal of Applied Physics 55 (2016) 05FC01[Non-patent document 1] H. Amano, Japanese Journal of Applied Physics 52 (2013) 050001[Non-patent document 2] J. Z. Domagala, et al., Journal of Crystal Growth 456 (2016) 80[Non-patent document 3] M. Iwinska, et al., Journal of Crystal Growth 456 (2016) 91[Non-patent document 4] M. Iwinska, et al., Journal of Crystal Growth 480 (2017) 102[Non-patent document 5] Y. Tsukada, et al., Japanese Journal of Applied Physics 55 (2016) 05FC01

[發明所欲解決之課題][The problem that the invention wants to solve]

本案發明人想到，能夠與以氨熱法成長之GaN結晶匹敵的、（004）XRD搖擺曲線FWHM在20arcsec以下的GaN結晶，若能夠以量產性優良的HVPE使其成長，就能夠促進開發將c面GaN晶圓用於基板所生產的氮化物半導體裝置，並對於低成本化有所貢獻。[解決課題之手段]The inventors of this case thought that if GaN crystals with a (004) XRD swing curve FWHM of less than 20 arcsec that can compete with GaN crystals grown by the ammonothermal method can be grown by HVPE with excellent mass production performance, it would be possible to promote the development of nitride semiconductor devices produced by using c-plane GaN wafers as substrates and contribute to cost reduction.[Means for Solving the Problem]

本發明的一面向係關於n型GaN結晶，另一面向係關於GaN晶圓，再一面向係關於GaN晶圓的製造方法，再另一面向係關於磊晶晶圓的製造方法，又一面向係關於磊晶晶圓，再另一面向係關於氮化物半導體裝置的製造方法，而再另一面向則係關於塊體GaN結晶的製造方法。One aspect of the present invention relates to n-type GaN crystals, another aspect relates to GaN wafers, another aspect relates to methods for manufacturing GaN wafers, another aspect relates to methods for manufacturing epitaxial wafers, another aspect relates to epitaxial wafers, another aspect relates to methods for manufacturing nitride semiconductor devices, and another aspect relates to methods for manufacturing bulk GaN crystals.

本發明的實施態樣包含以下的［A1］~［A26］，但不限於此等。［A1］一種n型GaN結晶：其所含有之最高濃度的施體雜質為Ge，並且具有小於0.03 Ω･cm的室溫電阻率，以及（004）XRD搖擺曲線FWHM小於20 arcsec、小於18 arcsec、小於16 arcsec、小於14 arcsec或小於12 arcsec。［A2］一種n型GaN結晶，其係如該［A1］之n型GaN結晶，其中該結晶具有互相朝向相反方向的2個主面，該2個主面的面積分別為3 cm²以上，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下。［A3］如該［A2］之n型GaN結晶，其具有20 mm以上、45 mm以上、95 mm以上或145 mm以上的直徑。［A4］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面之傾斜在0度以上10度以下的n型GaN結晶，其所含有之最高濃度的施體雜質為Ge，且其具有小於0.03 Ω･cm的室溫電阻率，以及在該一側的主面上沿著至少1條線於長度40 mm中每隔1mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。［A5］如該［A4］之n型GaN結晶，其中該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［A6］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，其所含有之最高濃度的施體雜質為Ge，且其具有小於0.03 Ω･cm的室溫電阻率，以及在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。［A7］如該［A6］之n型GaN結晶，其中該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［A8］如該［A2］~［A7］中任一項之n型GaN結晶，其具有小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［A9］如該［A2］~［A7］中任一項之n型GaN結晶，其載子濃度為1×10¹⁸cm^-3以上、2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上。［A10］如該［A2］~［A9］中任一項之n型GaN結晶，其中關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［A11］如該［A10］之n型GaN結晶，其滿足全數與雜質濃度相關的該條件（a）~（c）。［A12］如該［A2］~［A11］中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［A13］如該［A2］~［A12］中任一項之n型GaN結晶，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。［A14］如該［A2］~［A13］中任一項之n型GaN結晶，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［A15］如該［A2］~［A14］中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。［A16］一種GaN晶圓，其係由該［A2］~［A15］中任一項之n型GaN結晶所構成。［A17］一種GaN晶圓，其中如該［A2］~［A15］中任一項之n型GaN結晶所構成的第一區域設於Ga極性側，而載子濃度低於該n型GaN結晶的第二區域設於N極性側。［A18］如該［A17］之GaN晶圓，其中該第一區域的厚度為5 μm以上250 μm以下。［A19］如該［A17］或［A18］之GaN晶圓，其中該第二區域，關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［A20］如該［A19］之GaN晶圓，其中該第二區域滿足全數與雜質濃度相關的該條件（a）~（c）。［A21］如該［A17］~［A20］中任一項之GaN晶圓，其中該第二區域中的O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［A22］如該［A17］~［A21］中任一項之GaN晶圓，其中該第二區域中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［A23］如該［A17］~［A22］中任一項之GaN晶圓，其中該第一區域與該第二區域之間具有再成長界面。［A24］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［A16］~［A23］中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［A25］一種磊晶晶圓，其係由如該［A16］~［A23］中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［A26］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［A16］~［A23］中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。Embodiments of the present invention include the following [A1] to [A26], but are not limited thereto. [A1] An n-type GaN crystal: the highest concentration of donor impurities contained in the crystal is Ge, and the crystal has a room temperature resistivity of less than 0.03 Ω･cm, and a (004) XRD swing curve FWHM of less than 20 arcsec, less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, or less than 12 arcsec. [A2] An n-type GaN crystal, which is the n-type GaN crystal of [A1], wherein the crystal has two main surfaces facing in opposite directions, the areas of the two main surfaces are respectively greater than 3^cm2 , and one of the two main surfaces is Ga-polar and has a tilt of greater than 0 degrees and less than 10 degrees relative to the (0001) crystal plane. [A3] The n-type GaN crystal of [A2], having a diameter of 20 mm or more, 45 mm or more, 95 mm or more, or 145 mm or more. [A4] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to the (0001) crystal plane, wherein the highest concentration of the donor impurity contained in the n-type GaN crystal is Ge, and the crystal has a room temperature resistivity of less than 0.03 Ω･cm, and when the (004) XRD swing curve is measured at intervals of 1 mm along at least one line over a length of 40 mm on the principal surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is 20 arcsec or less. [A5] The n-type GaN crystal of [A4], wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec or less than 10 arcsec. [A6] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein the highest concentration of the donor impurity contained in the n-type GaN crystal is Ge, and the crystal has a room temperature resistivity of less than 0.03 Ω･cm, and when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the principal surface at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is not more than 20 arcsec. [A7] The n-type GaN crystal of [A6], wherein the average value of the FWHM of the (004) XRD swing curve between all the measurement points on each line is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec or less than 10 arcsec. [A8] The n-type GaN crystal of any one of [A2] to [A7], having a room temperature resistivity of less than 0.02 Ω･cm, less than 0.015 Ω･cm or less than 0.010 Ω･cm. [A9] The n-type GaN crystal of any one of [A2] to [A7], having a carrier concentration of 1×10¹⁸ cm^-3 or more, 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [A10] An n-type GaN crystal as described in any one of [A2] to [A9], wherein the impurity concentration satisfies one or more conditions selected from the following (a) to (c): (a) Si concentration is 5×10¹⁶ atoms/cm³ or more; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [A11] An n-type GaN crystal as described in [A10], which satisfies all of the conditions (a) to (c) related to impurity concentration. [A12] The n-type GaN crystal of any one of [A2] to [A11], wherein the O concentration is 3×10¹⁶ atoms/cm³ or less, 2×10¹⁶ atoms/cm³ or less, or 1×10¹⁶ atoms/cm³ or less. [A13] The n-type GaN crystal of any one of [A2] to [A12], wherein the Ge concentration is 1×10¹⁸ atoms/cm³ or more, and the Si concentration is 4×10¹⁷ atoms/cm³ or more. [A14] The n-type GaN crystal of any one of [A2] to [A13], wherein the concentration of each impurity other than Ge, Si, O and H is 5×10¹⁵ atoms/cm³ or less. [A15] An n-type GaN crystal as described in any one of [A2] to [A14], which is a GaN crystal grown by HVPE. [A16] A GaN wafer, which is composed of the n-type GaN crystal as described in any one of [A2] to [A15]. [A17] A GaN wafer, wherein a first region composed of the n-type GaN crystal as described in any one of [A2] to [A15] is located on the Ga polarity side, and a second region having a carrier concentration lower than that of the n-type GaN crystal is located on the N polarity side. [A18] A GaN wafer as described in [A17], wherein the thickness of the first region is not less than 5 μm and not more than 250 μm. [A19] A GaN wafer as described in [A17] or [A18], wherein the second region satisfies one or more of the following conditions (a) to (c) with respect to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm^3. [A20] A GaN wafer as described in [A19], wherein the second region satisfies all of the conditions (a) to (c) with respect to impurity concentration. [A21] A GaN wafer as described in any one of [A17] to [A20], wherein the O concentration in the second region is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [A22] A GaN wafer as described in any one of [A17] to [A21], wherein the concentration of each impurity in the second region, except for Si, O, and H, is less than 5×10¹⁵ atoms/cm^3. [A23] A GaN wafer as described in any one of [A17] to [A22], wherein a re-growth interface is present between the first region and the second region. [A24] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing a GaN wafer as described in any one of [A16] to [A23]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer. [A25] An epitaxial wafer, which comprises a GaN wafer as described in any one of [A16] to [A23] and one or more nitride semiconductor layers epitaxially grown on the GaN wafer. [A26] A method for manufacturing a nitride semiconductor device, comprising the following steps: preparing a GaN wafer as described in any one of [A16] to [A23]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.

本發明的實施態樣更包含以下的［B1］~［B29］。［B1］一種n型GaN結晶，其具有小於0.03 Ω･cm的室溫電阻率，且（004）XRD搖擺曲線FWHM小於20 arcsec，而關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［B2］一種n型GaN結晶，其係如該［B1］之n型GaN結晶，其中該結晶具有互相朝向相反方向的2個主面，該2個主面的面積分別為3 cm²以上，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下。［B3］如該［B2］之n型GaN結晶，其具有20 mm以上、45 mm以上、95 mm以上或145 mm以上的直徑。［B4］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，具有小於0.03 Ω･cm的室溫電阻率，在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［B5］如該［B4］之n型GaN結晶，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下或12 arcsec以下。［B6］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，具有小於0.03 Ω･cm的室溫電阻率，在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［B7］如該［B6］之n型GaN結晶，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下或12 arcsec以下。［B8］如該［B2］~［B7］中任一項之n型GaN結晶，其具有小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［B9］如該［B2］~［B7］中任一項之n型GaN結晶，其載子濃度為1×10¹⁸cm^-3以上或2×10¹⁸cm^-3以上。［B10］如該［B2］~［B9］中任一項之n型GaN結晶，其中關於雜質濃度滿足全數該條件（a）~（c）。［B11］如該［B2］~［B10］中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［B12］如該［B2］~［B11］中任一項之n型GaN結晶，其所含有之最高濃度的施體雜質為Si。［B13］如該［B12］之n型GaN結晶，其中Si以外之施體雜質之總濃度為Si濃度的10 %以下、5 %以下或1 %以下。［B14］如該［B13］之n型GaN結晶，其中載子濃度為Si濃度的90 %以上。［B15］如該［B2］~［B14］中任一項之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［B16］如該［B2］~［B12］中任一項之n型GaN結晶，其中Ge濃度為1×10¹⁸atoms/cm³以上、且Si濃度為4×10¹⁷atoms/cm³以上。［B17］如該［B16］之n型GaN結晶，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［B18］如該［B2］~［B17］中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。［B19］一種GaN晶圓，其係由如該［B2］~［B18］中任一項之n型GaN結晶所構成。［B20］一種GaN晶圓，其中如該［B2］~［B18］中任一項之n型GaN結晶所構成的第一區域設於Ga極性側，載子濃度低於該n型GaN結晶的第二區域設於N極性側。［B21］如該［B20］之GaN晶圓，其中該第一區域的厚度為5 μm以上250 μm以下。［B22］如該［B20］或［B21］之GaN晶圓，其中該第二區域，關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［B23］如該［B22］之GaN晶圓，其中該第二區域滿足全數與雜質濃度相關的該條件（a）~（c）。［B24］如該［B20］~［B23］中任一項之GaN晶圓，其中該第二區域中的O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［B25］如該［B20］~［B24］中任一項之GaN晶圓，其中該第二區域中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［B26］如該［B20］~［B25］中任一項之GaN晶圓，其中該第一區域與該第二區域之間具有再成長界面。［B27］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［B19］~［B26］中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［B28］一種磊晶晶圓，其係由如該［B19］~［B26］中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［B29］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［B19］~［B26］中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。Embodiments of the present invention further include the following [B1] to [B29]. [B1] An n-type GaN crystal having a room temperature resistivity of less than 0.03 Ω･cm and a (004) XRD swing curve FWHM of less than 20 arcsec, and satisfying one or more of the following conditions (a) to (c) regarding impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm³ . [B2] An n-type GaN crystal, which is the n-type GaN crystal of [B1], wherein the crystal has two main surfaces facing opposite directions, the area of the two main surfaces is 3^cm2 or more, and one of the two main surfaces is Ga polar and has an inclination of 0 degrees or more and 10 degrees or less relative to the (0001) crystal plane. [B3] The n-type GaN crystal of [B2] has a diameter of 20 mm or more, 45 mm or more, 95 mm or more, or 145 mm or more. [B4] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm, and when a (004) XRD swing curve is measured at intervals of 1 mm over a length of 40 mm along at least one line on the principal surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is not more than 20 arcsec, and the impurity concentration satisfies at least one condition selected from the following (a) to (c): (a) Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration is not less than 3×10¹⁶ atoms/cm 3; atoms/cm³ or less; (c) a H concentration of 1×10¹⁷ atoms/cm³ or less. [B5] The n-type GaN crystal of [B4], wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, or less than 12 arcsec. [B6] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm, and when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the principal surface at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is not more than 20 arcsec, and the impurity concentration satisfies at least one condition selected from the following (a) to (c): (a) Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [B7] The n-type GaN crystal of [B6], wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is 18 arcsec or less, 16 arcsec or less, 14 arcsec or less, or 12 arcsec or less. [B8] The n-type GaN crystal of any one of [B2] to [B7], having a room temperature resistivity of less than 0.02 Ω･cm, less than 0.015 Ω･cm, or less than 0.010 Ω･cm. [B9] The n-type GaN crystal of any one of [B2] to [B7], wherein the carrier concentration is 1×10¹⁸ cm^-3 or more or 2×10¹⁸ cm^-3 or more. [B10] The n-type GaN crystal of any one of [B2] to [B9], wherein the impurity concentration satisfies all of the conditions (a) to (c). [B11] The n-type GaN crystal of any one of [B2] to [B10], wherein the O concentration is 3×10¹⁶ atoms/cm³ or less, 2×10¹⁶ atoms/cm³ or less, or 1×10¹⁶ atoms/cm³ or less. [B12] The n-type GaN crystal of any one of [B2] to [B11], wherein the highest concentration of the donor impurity contained in the crystal is Si. [B13] The n-type GaN crystal of [B12], wherein the total concentration of donor impurities other than Si is less than 10%, less than 5%, or less than 1% of the Si concentration. [B14] The n-type GaN crystal of [B13], wherein the carrier concentration is greater than or equal to 90% of the Si concentration. [B15] The n-type GaN crystal of any one of [B2] to [B14], wherein the concentration of each impurity other than Si, O, and H is less than or equal to 5×10¹⁵ atoms/cm^3. [B16] The n-type GaN crystal of any one of [B2] to [B12], wherein the Ge concentration is greater than or equal to 1×10¹⁸ atoms/cm³ , and the Si concentration is greater than or equal to 4×10¹⁷ atoms/cm³ . [B17] An n-type GaN crystal as described in [B16], wherein the concentration of each impurity other than Ge, Si, O and H is less than 5×10¹⁵ atoms/cm^3. [B18] An n-type GaN crystal as described in any one of [B2] to [B17], which is a GaN crystal grown by HVPE. [B19] A GaN wafer, which is composed of an n-type GaN crystal as described in any one of [B2] to [B18]. [B20] A GaN wafer, wherein a first region composed of an n-type GaN crystal as described in any one of [B2] to [B18] is located on the Ga polarity side, and a second region having a carrier concentration lower than that of the n-type GaN crystal is located on the N polarity side. [B21] A GaN wafer as in [B20], wherein the thickness of the first region is greater than 5 μm and less than 250 μm. [B22] A GaN wafer as in [B20] or [B21], wherein the second region satisfies one or more of the following conditions (a) to (c) with respect to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm^3. [B23] A GaN wafer as in [B22], wherein the second region satisfies all of the conditions (a) to (c) with respect to impurity concentration. [B24] A GaN wafer as described in any one of [B20] to [B23], wherein the O concentration in the second region is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [B25] A GaN wafer as described in any one of [B20] to [B24], wherein the concentration of each impurity in the second region, except for Si, O, and H, is less than 5×10¹⁵ atoms/cm^3. [B26] A GaN wafer as described in any one of [B20] to [B25], wherein a re-growth interface is present between the first region and the second region. [B27] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing a GaN wafer as described in any one of [B19] to [B26]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer. [B28] An epitaxial wafer, which comprises a GaN wafer as described in any one of [B19] to [B26] and one or more nitride semiconductor layers epitaxially grown on the GaN wafer. [B29] A method for manufacturing a nitride semiconductor device, comprising the following steps: preparing a GaN wafer as described in any one of [B19] to [B26]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.

本發明的實施態樣更包含以下的［C1］~［C44］。［C1］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，具有45 mm以上的直徑，而（004）XRD搖擺曲線FWHM小於20 arcsec、小於18 arcsec、小於16 arcsec、小於14 arcsec或小於12 arcsec，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［C2］如該［C1］之n型GaN結晶，其具有95 mm以上或145 mm以上的直徑。［C3］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［C4］如該［C3］之n型GaN結晶，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10arcsec以下。［C5］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［C6］如該［C5］之n型GaN結晶，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［C7］如該［C1］~［C6］中任一項之n型GaN結晶，其中關於雜質濃度滿足全數該條件（a）~（c）。［C8］如該［C1］~［C7］中任一項之n型GaN結晶，其中Si濃度為5×10¹⁷atoms/cm³以下。［C9］如該［C1］~［C8］中任一項之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［C10］如該［C1］~［C9］中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［C11］如該［C1］~［C10］中任一項之n型GaN結晶，其具有小於5×10¹⁷cm^-3之載子濃度與0.04 Ω･cm以上之室溫電阻率中的至少任一者。［C12］如該［C1］~［C11］中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。［C13］如該［C1］~［C12］中任一項之n型GaN結晶所構成的GaN晶圓。［C14］一種雙層GaN晶圓，具有：底層，其係由如該［C1］~［C12］中任一項之n型GaN結晶所構成；及表層，其係由GaN所構成，隔著再成長界面形成於該n型GaN結晶的Ga極性側之主面上，且最小厚度為20 μm以上；在該表層中，從頂面至少距離5 μm以內的部分包含於高載子濃度區域，而該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域。［C15］如該［C14］之雙層GaN晶圓，其中在該表層中，從頂面至少20 μm以內的部分包含於該高載子濃度區域。［C16］如該［C14］或［C15］之雙層GaN晶圓，其中該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上的區域。［C17］如該［C14］~［C16］中任一項之雙層GaN晶圓，其中該表層，關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［C18］如該［C17］之雙層GaN晶圓，其中該表層滿足全數與雜質濃度相關的該條件（a）~（c）。［C19］如該［C14］~［C18］中任一項之雙層GaN晶圓，其中該表層中的O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［C20］如該［C14］~［C19］中任一項之雙層GaN晶圓，其中該高載子濃度區域摻雜有Si。［C21］如該［C20］之雙層GaN晶圓，其中在該表層中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［C22］如該［C14］~［C20］中任一項之雙層GaN晶圓，其中該高載子濃度區域摻雜有Ge。［C23］如該［C22］之雙層GaN晶圓，其中在該表層中，除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［C24］如該［C14］~［C23］中任一項之雙層GaN晶圓，其中該高載子濃度區域中，載子濃度或施體雜質的總濃度沿著c軸方向的變動，相較於中間值，係在±25 %以內、±20 %以內、±15 %以內或±10 %以內。［C25］一種雙層GaN晶圓，具有：底層，其係由如該［C1］~［C12］中任一項之n型GaN結晶所構成；及表層，其係由GaN所構成，隔著再成長界面形成於該n型GaN結晶的Ga極性側的主面上，且最小厚度為20 μm以上；該表層中，從頂面至少距離5 μm以內的部分包含於載子補償區域，該載子補償區域係補償雜質的總濃度下限為1×10¹⁷atoms/cm³以上的區域。［C26］如該［C25］之雙層GaN晶圓，其中在該表層中，從頂面至少20 μm以內的部分包含於該載子補償區域。［C27］如該［C25］或［C26］之雙層GaN晶圓，其中該載子補償區域，係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上、5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。［C28］如該［C25］~［C27］中任一項之雙層GaN晶圓，其中該表層，關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［C29］如該［C25］~［C28］中任一項之雙層GaN晶圓，其中在該載子補償區域中，補償雜質的總濃度沿著c軸方向的變動，相較於中間值，係在±25 %以內、±20 %以內、±15 %以內或±10 %以內。［C30］如該［C14］~［C29］中任一項之雙層GaN晶圓，其中該雙層GaN晶圓的厚度大於300 μm，該表層之最大厚度在300 μm以下、250 μm以下或200 μm以下。［C31］如該［C14］~［C30］中任一項之雙層GaN晶圓，其中該表層的最小厚度在50 μm以上、75 μm以上或100 μm以上。［C32］如該［C14］~［C31］中任一項之雙層GaN晶圓，其中該表層的最大厚度與最小厚度的差在200 μm以下、100 μm以下、50 μm以下、25 μm以下或10μm以下。［C33］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［C13］~［C32］中任一項之晶圓的步驟；及在該所準備之晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［C34］一種磊晶晶圓，其係由如該［C13］~［C32］中任一項之晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［C35］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［C13］~［C32］中任一項之晶圓的步驟；及在該所準備之晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［C36］一種雙層GaN晶圓的製造方法，具有下述步驟：準備如該［C13］之GaN晶圓的步驟；及在該所準備之GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，而該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。［C37］如該［C36］之製造方法，其中在該磊晶成長之步驟中，係以HVPE使該GaN層成長。［C38］如該［C36］或［C37］之製造方法，其中該GaN層的厚度為500 μm以下。［C39］如該［C36］~［C38］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上的區域。［C40］如該［C36］~［C39］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。［C41］如該［C36］~［C40］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意摻雜有Si。［C42］如該［C36］~［C38］中任一項之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域，係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。［C43］如該［C36］~［C42］中任一項之製造方法，其中更具有將該磊晶成長步驟中所得到的積層體薄化的步驟。［C44］一種塊體GaN結晶的製造方法，具有：準備如該［C13］之GaN晶圓的步驟；及在該所準備之GaN晶圓上使GaN磊晶成長的步驟。The implementation aspects of the present invention further include the following [C1] to [C44]. [C1] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, having a diameter of not less than 45 mm, and a (004) XRD wobble curve FWHM of less than 20 arcsec, less than 18 arcsec, less than 16 arcsec, less than 14 arcsec or less than 12 arcsec, and satisfying at least one of the following (a) to (c) conditions regarding impurity concentration: (a) Si concentration of not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration of not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration of not more than 1×10¹⁷ atoms/cm³ . [C2] The n-type GaN crystal of [C1], having a diameter of 95 mm or more or 145 mm or more. [C3] An n-type GaN crystal having two principal surfaces facing in opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured along at least one line on the principal surface at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is not more than 20 arcsec, and the impurity concentration satisfies at least one condition selected from the following (a) to (c): (a) Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration is not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm^3. [C4] The n-type GaN crystal of [C3], wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec or less than 10 arcsec. [C5] An n-type GaN crystal having two principal surfaces facing in opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the principal surface at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is not more than 20 arcsec, and the impurity concentration satisfies at least one of the following (a) to (c): (a) the Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) the O concentration is not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [C6] The n-type GaN crystal of [C5], wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is 18 arcsec or less, 16 arcsec or less, 14 arcsec or less, 12 arcsec or less, or 10 arcsec or less. [C7] The n-type GaN crystal of any one of [C1] to [C6], wherein all of the conditions (a) to (c) are satisfied with respect to impurity concentration. [C8] The n-type GaN crystal of any one of [C1] to [C7], wherein the Si concentration is 5×10¹⁷ atoms/cm³ or less. [C9] The n-type GaN crystal of any one of [C1] to [C8], wherein the concentration of each impurity other than Si, O and H is 5×10¹⁵ atoms/cm³ or less. [C10] The n-type GaN crystal of any one of [C1] to [C9], wherein the concentration of O is 3×10¹⁶ atoms/cm³ or less, 2×10¹⁶ atoms/cm³ or less, or 1×10¹⁶ atoms/cm³ or less. [C11] The n-type GaN crystal of any one of [C1] to [C10], having at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of 0.04 Ω･cm or more. [C12] An n-type GaN crystal as described in any one of [C1] to [C11], which is a GaN crystal grown by HVPE. [C13] A GaN wafer composed of an n-type GaN crystal as described in any one of [C1] to [C12]. [C14] A double-layer GaN wafer, comprising: a bottom layer, which is composed of an n-type GaN crystal as described in any one of [C1] to [C12]; and a surface layer, which is composed of GaN, formed on the main surface of the Ga polar side of the n-type GaN crystal via a re-growth interface, and has a minimum thickness of 20 μm or more; in the surface layer, a portion at least 5 μm from the top surface is included in a high carrier concentration region, and the high carrier concentration region is a region with a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more. [C15] A double-layer GaN wafer as described in [C14], wherein in the surface layer, a portion at least 20 μm from the top surface is included in the high carrier concentration region. [C16] A double-layer GaN wafer as described in [C14] or [C15], wherein the high carrier concentration region is a region having a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [C17] A double-layer GaN wafer as described in any one of [C14] to [C16], wherein the surface layer satisfies one or more of the following (a) to (c) conditions regarding impurity concentration: (a) Si concentration is 5×10¹⁶ atoms/cm³ or more; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [C18] A double-layer GaN wafer as described in [C17], wherein the surface layer satisfies all of the conditions (a) to (c) related to impurity concentration. [C19] A double-layer GaN wafer as described in any one of [C14] to [C18], wherein the O concentration in the surface layer is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [C20] A double-layer GaN wafer as described in any one of [C14] to [C19], wherein the high carrier concentration region is doped with Si. [C21] A double-layer GaN wafer as described in [C20], wherein in the surface layer, except for Si, O and H, the concentration of each impurity is less than 5×10¹⁵ atoms/cm^3. [C22] A double-layer GaN wafer as described in any one of [C14] to [C20], wherein the high carrier concentration region is doped with Ge. [C23] A double-layer GaN wafer as described in [C22], wherein in the surface layer, except for Ge, Si, O and H, the concentration of each impurity is less than 5×10¹⁵ atoms/cm³ . [C24] A double-layer GaN wafer as described in any one of [C14] to [C23], wherein the variation of the carrier concentration or the total concentration of donor impurities in the high carrier concentration region along the c-axis direction is within ±25%, within ±20%, within ±15%, or within ±10% relative to the median value. [C25] A double-layer GaN wafer comprising: a bottom layer composed of an n-type GaN crystal as described in any one of [C1] to [C12]; and a surface layer composed of GaN, formed on a main surface of the Ga polar side of the n-type GaN crystal via a re-growth interface, and having a minimum thickness of 20 μm or more; a portion of the surface layer at least 5 μm away from the top surface is included in a carrier compensation region, and the carrier compensation region is a region where the lower limit of the total concentration of compensation impurities is 1×10¹⁷ atoms/cm³ or more. [C26] The double-layer GaN wafer of [C25], wherein in the surface layer, a portion at least within 20 μm from the top surface is included in the carrier compensation region. [C27] The double-layer GaN wafer of [C25] or [C26], wherein the carrier compensation region is a region where the lower limit of the total concentration of compensation impurities is 2×10¹⁷ atoms/cm³ or more, 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. [C28] A double-layer GaN wafer as described in any one of [C25] to [C27], wherein the surface layer satisfies one or more of the following (a) to (c) conditions regarding impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm³ . [C29] A double-layer GaN wafer as described in any one of [C25] to [C28], wherein in the carrier compensation region, the variation of the total concentration of the compensation impurities along the c-axis direction is within ±25%, within ±20%, within ±15%, or within ±10% relative to the median value. [C30] A double-layer GaN wafer as described in any one of [C14] to [C29], wherein the thickness of the double-layer GaN wafer is greater than 300 μm, and the maximum thickness of the surface layer is less than 300 μm, less than 250 μm, or less than 200 μm. [C31] A double-layer GaN wafer as described in any one of [C14] to [C30], wherein the minimum thickness of the surface layer is greater than 50 μm, greater than 75 μm, or greater than 100 μm. [C32] A double-layer GaN wafer as described in any one of [C14] to [C31], wherein the difference between the maximum thickness and the minimum thickness of the surface layer is less than 200 μm, less than 100 μm, less than 50 μm, less than 25 μm, or less than 10 μm. [C33] A method for manufacturing an epitaxial wafer, comprising the following steps: a step of preparing a wafer as described in any one of [C13] to [C32]; and a step of epitaxially growing one or more nitride semiconductor layers on the prepared wafer. [C34] An epitaxial wafer, which is composed of a wafer as described in any one of [C13] to [C32] and one or more nitride semiconductor layers epitaxially grown on the GaN wafer. [C35] A method for manufacturing a nitride semiconductor device, which is composed of the following steps: preparing a wafer as described in any one of [C13] to [C32]; and epitaxially growing one or more nitride semiconductor layers on the prepared wafer. [C36] A method for manufacturing a double-layer GaN wafer, comprising the following steps: a step of preparing a GaN wafer as described in [C13]; and a step of epitaxially growing a GaN layer having a thickness of 20 μm or more on the main surface of the Ga polar side of the prepared GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region having a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more, and the carrier compensation region is a region having a total concentration lower limit of compensation impurities of 2×10¹⁷ atoms/cm³ or more. [C37] The manufacturing method of [C36], wherein in the step of epitaxial growth, the GaN layer is grown by HVPE. [C38] The manufacturing method of [C36] or [C37], wherein the thickness of the GaN layer is less than 500 μm. [C39] The manufacturing method of any one of [C36] to [C38], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region having a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [C40] The manufacturing method of any one of [C36] to [C39], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge. [C41] The manufacturing method of any one of [C36] to [C40], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is intentionally doped with Si. [C42] A manufacturing method as described in any one of [C36] to [C38], wherein the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the carrier compensation region is 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. [C43] A manufacturing method as described in any one of [C36] to [C42], wherein the step of thinning the laminate obtained in the epitaxial growth step is further included. [C44] A method for manufacturing bulk GaN crystals, comprising: a step of preparing a GaN wafer as described in [C13]; and a step of epitaxially growing GaN on the prepared GaN wafer.

本發明的實施態樣更包含以下的［D1］~［D19］。［D1］一種c面GaN晶圓：其所含有之最高濃度的施體雜質為Ge，其導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，以及（004）XRD搖擺曲線FWHM小於20 arcsec、小於18 arcsec、小於16 arcsec、小於14 arcsec或小於12 arcsec。［D2］如該［D1］之c面GaN晶圓，其具備面積3 cm²以上的主面。［D3］如該［D1］之c面GaN晶圓，其具有20 mm以上、45 mm以上、95 mm以上或145 mm以上的直徑。［D4］一種c面GaN晶圓：其所含有之最高濃度的施體雜質為Ge，其導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，以及在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。［D5］如該［D4］之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［D6］一種c面GaN晶圓：其所含有之最高濃度的施體雜質為Ge，其導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，以及在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。［D7］如該［D6］之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［D8］如該［D1］~［D7］中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線上的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內，分別在0.15度以下、0.1度以下、或0.08度以下。［D9］如該［D1］~［D8］中任一項之c面GaN晶圓，其具有小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［D10］如該［D1］~［D8］中任一項之c面GaN晶圓，其中載子濃度為1×10¹⁸cm^-3以上、2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上。［D11］如該［D1］~［D10］中任一項之c面GaN晶圓，其中關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［D12］如該［D11］之c面GaN晶圓，其滿足全數與雜質濃度相關的該條件（a）~（c）。［D13］如該［D1］~［D12］中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［D14］如該［D1］~［D13］中任一項之c面GaN晶圓，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。［D15］如該［D1］~［D14］中任一項之c面GaN晶圓，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［D16］如該［D1］~［D15］中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。［D17］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［D1］~［D16］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［D18］一種磊晶晶圓，其係由如該［D1］~［D16］中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［D19］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［D1］~［D16］中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。Embodiments of the present invention further include the following [D1] to [D19]. [D1] A c-plane GaN wafer: the highest concentration of donor impurities contained in the wafer is Ge, the conductivity type is n-type, and the wafer has a room temperature resistivity of less than 0.03 Ω･cm, and a (004) XRD swing curve FWHM of less than 20 arcsec, less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, or less than 12 arcsec. [D2] The c-plane GaN wafer of [D1], having a main surface with an area of 3^cm2 or more. [D3] The c-plane GaN wafer of [D1], having a diameter of 20 mm or more, 45 mm or more, 95 mm or more, or 145 mm or more. [D4] A c-plane GaN wafer: the highest concentration of the donor impurity contained in the wafer is Ge, the conductivity type is n-type, and the wafer has a room temperature resistivity of less than 0.03 Ω･cm, and when the (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on a principal surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec. [D5] A c-plane GaN wafer as described in [D4], wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec, or less than 10 arcsec. [D6] A c-plane GaN wafer: the highest concentration of the donor impurity contained in the wafer is Ge, the conductivity type is n-type, and the wafer has a room temperature resistivity of less than 0.03 Ω･cm, and when the (004) XRD swing curve is measured along at least two mutually perpendicular lines on one main surface at intervals of 1 mm in a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all the measurement points on each line is less than 20 arcsec. [D7] The c-plane GaN wafer of [D6], wherein the average value of the FWHM of the (004) XRD swing curve between all the measurement points on each line is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec, or less than 10 arcsec. [D8] A c-plane GaN wafer as described in any one of [D1] to [D7], wherein the variation of the x-direction component of the cut angle on a line extending in the x-direction through the center of the surface and the variation of the y-direction component of the cut angle on a line extending in the y-direction perpendicular to the x-direction through the center of the surface are less than 0.15 degrees, less than 0.1 degrees, or less than 0.08 degrees within a length range of 40 mm. [D9] A c-plane GaN wafer as described in any one of [D1] to [D8], having a room temperature resistivity of less than 0.02 Ω･cm, less than 0.015 Ω･cm, or less than 0.010 Ω･cm. [D10] A c-plane GaN wafer as described in any one of [D1] to [D8], wherein the carrier concentration is 1×10¹⁸ cm^-3 or more, 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [D11] A c-plane GaN wafer as described in any one of [D1] to [D10], wherein the impurity concentration satisfies one or more of the following (a) to (c): (a) Si concentration is 5×10¹⁶ atoms/cm³ or more; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [D12] The c-plane GaN wafer of [D11], which satisfies all of the conditions (a) to (c) related to impurity concentration. [D13] The c-plane GaN wafer of any one of [D1] to [D12], wherein the O concentration is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [D14] The c-plane GaN wafer of any one of [D1] to [D13], wherein the Ge concentration is greater than 1×10¹⁸ atoms/cm³ , and the Si concentration is greater than 4×10¹⁷ atoms/cm³ . [D15] A c-plane GaN wafer as described in any one of [D1] to [D14], wherein the concentration of each impurity other than Ge, Si, O and H is less than 5×10¹⁵ atoms/cm^3. [D16] A c-plane GaN wafer as described in any one of [D1] to [D15], which is composed of GaN crystals grown by HVPE. [D17] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing a c-plane GaN wafer as described in any one of [D1] to [D16]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer. [D18] An epitaxial wafer, which is composed of a GaN wafer as described in any one of [D1] to [D16] and one or more nitride semiconductor layers epitaxially grown on the GaN wafer. [D19] A method for manufacturing a nitride semiconductor device, which is composed of the following steps: preparing a GaN wafer as described in any one of [D1] to [D16]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.

本發明的實施態樣更包含以下的［E1］~［E20］。［E1］一種c面GaN晶圓：導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，（004）XRD搖擺曲線FWHM小於20 arcsec，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［E2］如該［E1］之c面GaN晶圓，其具備面積3 cm²以上的主面。［E3］如該［E1］之c面GaN晶圓，其具有20 mm以上、45 mm以上、95 mm以上或145 mm以上的直徑。［E4］一種c面GaN晶圓：其導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［E5］如該［E4］之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下或12 arcsec以下。［E6］一種c面GaN晶圓：其導電型為n型，且具有小於0.03 Ω･cm的室溫電阻率，在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［E7］如該［E6］之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下或12 arcsec以下。［E8］如該［E1］~［E7］中任一項之c面GaN晶圓，其中切割角（off-cut angle）之x方向分量在通過表面中心而在x方向上延伸之線上的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下、0.1度以下、或0.08度以下。［E9］如該［E1］~［E8］中任一項之c面GaN晶圓，其具有小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［E10］如該［E1］~［E8］中任一項之c面GaN晶圓，其中載子濃度為1×10¹⁸cm^-3以上或2×10¹⁸cm^-3以上。［E11］如該［E1］~［E10］中任一項之c面GaN晶圓，其中關於雜質濃度滿足全數該條件（a）~（c）。［E12］如該［E1］~［E11］中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［E13］如該［E1］~［E12］中任一項之c面GaN晶圓，其所含有之最高濃度的施體雜質為Si。［E14］如該［E13］之c面GaN晶圓，其中Si以外之施體雜質的總濃度為Si濃度的10 %以下、5 %以下或1 %以下。［E15］如該［E14］之c面GaN晶圓，其中載子濃度為Si濃度的90 %以上。［E16］如該［E1］~［E15］中任一項之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［E17］如該［E1］~［E16］中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。［E18］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［E1］~［E17］中任一項之c面GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［E19］一種磊晶晶圓，其係由如該［E1］~［E17］中任一項之c面GaN晶圓與在該c面GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［E20］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［E1］~［E17］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。Embodiments of the present invention further include the following [E1] to [E20]. [E1] A c-plane GaN wafer: having an n-type conductivity, a room temperature resistivity of less than 0.03 Ω･cm, a (004) XRD swing curve FWHM of less than 20 arcsec, and an impurity concentration satisfying one or more of the following (a) to (c): (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm^3. [E2] The c-plane GaN wafer of [E1], having a main surface with an area of more than 3 cm² . [E3] The c-plane GaN wafer of [E1], having a diameter of greater than 20 mm, greater than 45 mm, greater than 95 mm, or greater than 145 mm. [E4] A c-plane GaN wafer: having an n-type conductivity and a room temperature resistivity of less than 0.03 Ω･cm, wherein when a (004) XRD swing curve is measured at intervals of 1 mm over a length of 40 mm along at least one line on a principal surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is 20 arcsec or less, and the impurity concentration satisfies one or more of the following (a) to (c): (a) Si concentration is 5×10¹⁶ atoms/cm³ or more; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [E5] The c-plane GaN wafer of [E4], wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, or less than 12 arcsec. [E6] A c-plane GaN wafer: having an n-type conductivity and a room temperature resistivity of less than 0.03 Ω･cm, wherein when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on a main surface of one side at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec, and the impurity concentration satisfies at least one of the following (a) to (c): (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm³ . [E7] A c-plane GaN wafer as described in [E6], wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, or less than 12 arcsec. [E8] A c-plane GaN wafer as described in any one of [E1] to [E7], wherein the variation of the x-direction component of the off-cut angle on a line extending in the x-direction through the center of the surface and the variation of the y-direction component of the off-cut angle on a line extending in the y-direction through the center of the surface and perpendicular to the x-direction are less than 0.15 degrees, less than 0.1 degrees, or less than 0.08 degrees, respectively, within a length interval of 40 mm. [E9] A c-plane GaN wafer as described in any one of [E1] to [E8], having a room temperature resistivity of less than 0.02 Ω･cm, less than 0.015 Ω･cm, or less than 0.010 Ω･cm. [E10] A c-plane GaN wafer as described in any one of [E1] to [E8], wherein the carrier concentration is greater than 1×10¹⁸ cm^-3 or greater than 2×10¹⁸ cm^-3 . [E11] A c-plane GaN wafer as described in any one of [E1] to [E10], wherein the impurity concentration satisfies all of the conditions (a) to (c). [E12] A c-plane GaN wafer as described in any one of [E1] to [E11], wherein the O concentration is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [E13] A c-plane GaN wafer as described in any one of [E1] to [E12], wherein the highest concentration of the donor impurity contained therein is Si. [E14] A c-plane GaN wafer as described in [E13], wherein the total concentration of donor impurities other than Si is less than 10%, less than 5%, or less than 1% of the Si concentration. [E15] A c-plane GaN wafer as described in [E14], wherein the carrier concentration is greater than 90% of the Si concentration. [E16] A c-plane GaN wafer as described in any one of [E1] to [E15], wherein the concentration of each impurity other than Si, O and H is less than 5×10¹⁵ atoms/cm^3. [E17] A c-plane GaN wafer as described in any one of [E1] to [E16], which is composed of GaN crystals grown by HVPE. [E18] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing a c-plane GaN wafer as described in any one of [E1] to [E17]; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer. [E19] An epitaxial wafer, which is composed of a c-plane GaN wafer as described in any one of [E1] to [E17] and one or more nitride semiconductor layers epitaxially grown on the c-plane GaN wafer. [E20] A method for manufacturing a nitride semiconductor device, which is composed of the following steps: preparing a c-plane GaN wafer as described in any one of [E1] to [E17]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer.

本發明的實施態樣更包含以下的［F1］~［F25］。［F1］一種c面GaN晶圓：其導電型為n型，具有45 mm以上的直徑，（004）XRD搖擺曲線FWHM小於20 arcsec、小於18 arcsec、小於16 arcsec、小於14 arcsec或小於12 arcsec，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［F2］如該［F1］之c面GaN晶圓，其具有95 mm以上或14 5mm以上的直徑。［F3］一種c面GaN晶圓：其導電型為n型，在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［F4］如該［F3］之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［F5］一種c面GaN晶圓：其導電型為n型，在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［F6］如該［F5］之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下、16 arcsec以下、14 arcsec以下、12 arcsec以下或10 arcsec以下。［F7］如該［F1］~［F6］中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下、0.1度以下、或0.08度以下。［F8］如該［F1］~［F7］中任一項之c面GaN晶圓，其中關於雜質濃度滿足全數該條件（a）~（c）。［F9］如該［F1］~［F8］中任一項之c面GaN晶圓，其中Si濃度為5×10¹⁷atoms/cm³以下。［F10］如該［F1］~［F9］中任一項之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［F11］如該［F1］~［F10］中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［F12］如該［F1］~［F11］中任一項之c面GaN晶圓，其具有小於5×10¹⁷cm^-3的載子濃度與0.04 Ω･cm以上的室溫電阻率中的至少任一者。［F13］如該［F1］~［F12］中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。［F14］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［F1］~［F13］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［F15］一種磊晶晶圓，其係由如該［F1］~［F13］中任一項之c面GaN晶圓與在該c面GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［F16］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［F1］~［F13］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［F17］一種雙層GaN晶圓的製造方法，具有：準備如該［F1］~［F13］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。［F18］如該［F17］之製造方法，其中在該磊晶成長之步驟中，係以HVPE使該GaN層成長。［F19］如該［F17］或［F18］之製造方法，其中該GaN層的厚度為500 μm以下。［F20］如該［F17］~［F19］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上的區域。［F21］如該［F17］~［F20］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。［F22］如該［F17］~［F21］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意地摻雜有Si。［F23］如該［F17］~［F19］中任一項之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域，係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。［F24］如該［F17］~［F23］中任一項之製造方法，其更具有將該磊晶成長之步驟中所得到之積層體薄化的步驟。［F25］一種塊體GaN結晶的製造方法，具有：準備如該［F1］~［F13］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使GaN磊晶成長的步驟。Embodiments of the present invention further include the following [F1] to [F25]. [F1] A c-plane GaN wafer: its conductivity type is n-type, has a diameter of 45 mm or more, (004) XRD swing curve FWHM is less than 20 arcsec, less than 18 arcsec, less than 16 arcsec, less than 14 arcsec or less than 12 arcsec, and the impurity concentration satisfies one or more conditions selected from the following (a) to (c): (a) Si concentration is 5×10¹⁶ atoms/cm³ or more; (b) O concentration is 3×10¹⁶ atoms/cm³ or less; (c) H concentration is 1×10¹⁷ atoms/cm³ or less. [F2] A c-plane GaN wafer as described in [F1], having a diameter of 95 mm or more or 14 5 mm or more. [F3] A c-plane GaN wafer: its conductivity type is n-type, and when the (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on a main surface of one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec, and the impurity concentration satisfies one or more conditions selected from the following (a) to (c): (a) Si concentration is more than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm³ . [F4] The c-plane GaN wafer of [F3], wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec or less than 10 arcsec. [F5] A c-plane GaN wafer: its conductivity type is n-type, and when the (004) XRD swing curve is measured at intervals of 1 mm along at least two mutually perpendicular lines in a length of 40 mm on a main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec, and the impurity concentration satisfies one or more conditions selected from the following (a) to (c): (a) Si concentration is more than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm³ . [F6] A c-plane GaN wafer as described in [F5], wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 18 arcsec, less than 16 arcsec, less than 14 arcsec, less than 12 arcsec, or less than 10 arcsec. [F7] A c-plane GaN wafer as described in any one of [F1] to [F6], wherein the variation of the x-direction component of the cut angle on a line extending in the x-direction through the center of the surface and the variation of the y-direction component of the cut angle on a line extending in the y-direction through the center of the surface and perpendicular to the x-direction are less than 0.15 degrees, less than 0.1 degrees, or less than 0.08 degrees, respectively, within a length interval of 40 mm. [F8] A c-plane GaN wafer as described in any one of [F1] to [F7], wherein the impurity concentration satisfies all of the conditions (a) to (c). [F9] A c-plane GaN wafer as described in any one of [F1] to [F8], wherein the Si concentration is 5×10¹⁷ atoms/cm³ or less. [F10] A c-plane GaN wafer as described in any one of [F1] to [F9], wherein the concentration of each impurity other than Si, O and H is 5×10¹⁵ atoms/cm³ or less. [F11] A c-plane GaN wafer as described in any one of [F1] to [F10], wherein the O concentration is 3×10¹⁶ atoms/cm³ or less, 2×10¹⁶ atoms/cm³ or less, or 1×10¹⁶ atoms/cm³ or less. [F12] A c-plane GaN wafer as described in any one of [F1] to [F11], having at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of 0.04 Ω･cm or more. [F13] A c-plane GaN wafer as described in any one of [F1] to [F12], comprising GaN crystals grown by HVPE. [F14] A method for manufacturing an epitaxial wafer, comprising the following steps: preparing a c-plane GaN wafer as described in any one of [F1] to [F13]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer. [F15] An epitaxial wafer, which is composed of a c-plane GaN wafer as described in any one of [F1] to [F13] and one or more nitride semiconductor layers epitaxially grown on the c-plane GaN wafer. [F16] A method for manufacturing a nitride semiconductor device, which is composed of the following steps: preparing a c-plane GaN wafer as described in any one of [F1] to [F13]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer. [F17] A method for manufacturing a double-layer GaN wafer, comprising: a step of preparing a c-plane GaN wafer as described in any one of [F1] to [F13]; and a step of epitaxially growing a GaN layer having a thickness of 20 μm or more on the main surface of the Ga-polar side of the prepared c-plane GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region having a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more, and the carrier compensation region is a region having a total concentration lower limit of compensation impurities of 2×10¹⁷ atoms/cm³ or more. [F18] The manufacturing method of [F17], wherein in the step of epitaxial growth, the GaN layer is grown by HVPE. [F19] The manufacturing method of [F17] or [F18], wherein the thickness of the GaN layer is 500 μm or less. [F20] The manufacturing method of any one of [F17] to [F19], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region having a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [F21] The manufacturing method of any one of [F17] to [F20], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge. [F22] The manufacturing method of any one of [F17] to [F21], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is intentionally doped with Si. [F23] A manufacturing method as described in any one of [F17] to [F19], wherein the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the carrier compensation region is 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. [F24] A manufacturing method as described in any one of [F17] to [F23], further comprising the step of thinning the laminate obtained in the step of epitaxial growth. [F25] A method for manufacturing bulk GaN crystals, comprising: preparing a c-plane GaN wafer as described in any one of [F1] to [F13]; and epitaxially growing GaN on the prepared c-plane GaN wafer.

本發明的實施態樣更包含以下的［G1］~［G29］。［G1］一種c面GaN晶圓：其導電型為n型，在一側的主面中，差排密度為2×10⁵cm^-2以下、1×10⁵cm^-2以下、或5×10⁴cm^-2以下，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［G2］如該［G1］之c面GaN晶圓，其中關於雜質濃度滿足全數該條件（a）~（c）。［G3］如該［G1］或［G2］之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［G4］如該［G1］~［G3］中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下、0.1度以下、或0.08度以下。［G5］如該［G1］~［G4］中任一項之c面GaN晶圓，其具有小於5×10¹⁷cm^-3的載子濃度與0.04 Ω･cm以上的室溫電阻率中的至少任一者。［G6］如該［G1］~［G5］中任一項之c面GaN晶圓，其中Si濃度為5×10¹⁷atoms/cm³以下。［G7］如該［G6］之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［G8］如該［G1］~［G4］中任一項之c面GaN晶圓，其具有小於0.03 Ω･cm、小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［G9］如該［G1］~［G4］中任一項之c面GaN晶圓，其中載子濃度為1×10¹⁸cm^-3以上、2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上。［G10］如該［G8］或［G9］之c面GaN晶圓，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。［G11］如該［G8］~［G10］中任一項之c面GaN晶圓，其所含有之最高濃度的施體雜質為Ge。［G12］如該［G10］或［G11］之c面GaN晶圓，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［G13］如該［G8］或［G9］中任一項之c面GaN晶圓，其所含有之最高濃度的施體雜質為Si。［G14］如該［G13］之c面GaN晶圓，其中Si以外之施體雜質的總濃度為Si濃度的10 %以下、5%以下或1 %以下。［G15］如該［G14］之c面GaN晶圓，其中載子濃度為Si濃度的90 %以上。［G16］如該［G13］~［G15］中任一項之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［G17］如該［G1］~［G16］中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。［G18］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［G1］~［G17］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［G19］一種磊晶晶圓，其係由如該［G1］~［G17］中任一項之c面GaN晶圓與在該c面GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。［G20］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［G1］~［G17］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。［G21］一種雙層GaN晶圓的製造方法，具有：準備如該［G1］~［G7］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。［G22］如該［G21］之製造方法，其中在該磊晶成長之步驟中，係以HVPE使該GaN層成長。［G23］如該［G21］或［G22］之製造方法，其中該GaN層的厚度為500 μm以下。［G24］如該［G21］~［G23］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上的區域。［G25］如該［G21］~［G24］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。［G26］如該［G21］~［G25］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意地摻雜有Si。［G27］如該［G21］~［G23］中任一項之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。［G28］如該［G21］~［G27］中任一項之製造方法，其更具有將在該磊晶成長之步驟中所得到的積層體薄化的步驟。［G29］一種塊體GaN結晶的製造方法，具有：準備如該［G1］~［G7］中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使GaN磊晶成長的步驟。The embodiments of the present invention further include the following [G1] to [G29]. [G1] A c-plane GaN wafer: its conductivity type is n-type, and in one main surface, the dislocation density is less than 2×10⁵ cm^-2 , less than 1×10⁵ cm^-2 , or less than 5×10⁴ cm^-2 , and the impurity concentration satisfies one or more conditions selected from the following (a) to (c): (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ ; (b) O concentration is less than 3×10¹⁶ atoms/cm³ ; (c) H concentration is less than 1×10¹⁷ atoms/cm^3. [G2] A c-plane GaN wafer as described in [G1], wherein the impurity concentration satisfies all of the conditions (a) to (c). [G3] A c-plane GaN wafer as described in [G1] or [G2], wherein the O concentration is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm^3. [G4] A c-plane GaN wafer as described in any one of [G1] to [G3], wherein the variation of the x-direction component of the cut angle on a line extending in the x-direction through the center of the surface and the variation of the y-direction component of the cut angle on a line extending in the y-direction through the center of the surface and perpendicular to the x-direction are less than 0.15 degrees, less than 0.1 degrees, or less than 0.08 degrees, respectively, within a length range of 40 mm. [G5] A c-plane GaN wafer as described in any one of [G1] to [G4], having at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of 0.04 Ω･cm or more. [G6] A c-plane GaN wafer as described in any one of [G1] to [G5], wherein the Si concentration is 5×10¹⁷ atoms/cm³ or less. [G7] A c-plane GaN wafer as described in [G6], wherein the concentration of each impurity other than Si, O and H is 5×10¹⁵ atoms/cm³ or less. [G8] The c-plane GaN wafer of any one of [G1] to [G4], having a room temperature resistivity of less than 0.03 Ω･cm, less than 0.02 Ω･cm, less than 0.015 Ω･cm, or less than 0.010 Ω･cm. [G9] The c-plane GaN wafer of any one of [G1] to [G4], wherein the carrier concentration is greater than or equal to 1×10¹⁸ cm^-3 , greater than or equal to 2×10¹⁸ cm^-3 , greater than or equal to 3×10¹⁸ cm^-3 , or greater than or equal to 4×10¹⁸ cm^-3 . [G10] The c-plane GaN wafer of [G8] or [G9], wherein the Ge concentration is greater than or equal to 1×10¹⁸ atoms/cm³ , and the Si concentration is greater than or equal to 4×10¹⁷ atoms/cm³ . [G11] The c-plane GaN wafer of any one of [G8] to [G10], wherein the highest concentration of the donor impurity contained therein is Ge. [G12] The c-plane GaN wafer of [G10] or [G11], wherein the concentration of each impurity other than Ge, Si, O and H is less than 5×10¹⁵ atoms/cm^3. [G13] The c-plane GaN wafer of any one of [G8] or [G9], wherein the highest concentration of the donor impurity contained therein is Si. [G14] The c-plane GaN wafer of [G13], wherein the total concentration of the donor impurities other than Si is less than 10%, less than 5% or less than 1% of the concentration of Si. [G15] A c-plane GaN wafer as in [G14], wherein the carrier concentration is greater than 90% of the Si concentration. [G16] A c-plane GaN wafer as in any one of [G13] to [G15], wherein the concentration of each impurity other than Si, O and H is less than 5×10¹⁵ atoms/cm^3. [G17] A c-plane GaN wafer as in any one of [G1] to [G16], wherein the wafer is composed of GaN crystals grown by HVPE. [G18] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing a c-plane GaN wafer as described in any one of [G1] to [G17]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer. [G19] An epitaxial wafer, which comprises a c-plane GaN wafer as described in any one of [G1] to [G17] and one or more nitride semiconductor layers epitaxially grown on the c-plane GaN wafer. [G20] A method for manufacturing a nitride semiconductor device, comprising the following steps: preparing a c-plane GaN wafer as described in any one of [G1] to [G17]; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer. [G21] A method for manufacturing a double-layer GaN wafer, comprising: preparing a c-plane GaN wafer as described in any one of [G1] to [G7]; and epitaxially growing a GaN layer having a thickness of 20 μm or more on the main surface of the Ga-polar side of the prepared c-plane GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region having a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more, and the carrier compensation region is a region having a total concentration lower limit of compensation impurities of 2×10¹⁷ atoms/cm³ or more. [G22] The manufacturing method of [G21], wherein in the step of epitaxial growth, the GaN layer is grown by HVPE. [G23] The manufacturing method of [G21] or [G22], wherein the thickness of the GaN layer is 500 μm or less. [G24] The manufacturing method of any one of [G21] to [G23], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region having a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [G25] The manufacturing method of any one of [G21] to [G24], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge. [G26] The manufacturing method of any one of [G21] to [G25], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is intentionally doped with Si. [G27] A manufacturing method as described in any one of [G21] to [G23], wherein the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the carrier compensation region is 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. [G28] A manufacturing method as described in any one of [G21] to [G27], further comprising the step of thinning the laminate obtained in the epitaxial growth step. [G29] A method for manufacturing bulk GaN crystals, comprising: preparing a c-plane GaN wafer as described in any one of [G1] to [G7]; and epitaxially growing GaN on the prepared c-plane GaN wafer.

本發明的實施態樣更包含以下的［H1］~［H32］。［H1］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，可得到至少一個10 mm×10 mm的正方形區域的X射線異常穿透像，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［H2］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，可得到至少一個15 mm×15 mm的正方形區域的X射線異常穿透像，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［H3］一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶，可得到至少一個20 mm×20 mm的正方形區域的X射線異常穿透像，以及關於雜質濃度滿足選自下述（a）~（c）中的一個以上的條件：（a）Si濃度為5×10¹⁶atoms/cm³以上；（b）O濃度為3×10¹⁶atoms/cm³以下；（c）H濃度為1×10¹⁷atoms/cm³以下。［H4］如該［H1］~［H3］中任一項之n型GaN結晶，其中關於雜質濃度滿足全數該條件（a）~（c）。［H5］如該［H1］~［H4］中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下。［H6］如該［H1］~［H5］中任一項之n型GaN結晶，其具有小於5×10¹⁷cm^-3的載子濃度與0.04 Ω･cm以上的室溫電阻率中的至少任一者。［H7］如該［H1］~［H6］中任一項之n型GaN結晶，其中Si濃度為5×10¹⁷atoms/cm³以下。［H8］如該［H7］之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［H9］如該［H1］~［H5］中任一項之n型GaN結晶，其具有小於0.03 Ω･cm、小於0.02 Ω･cm、小於0.015 Ω･cm或小於0.010 Ω･cm的室溫電阻率。［H10］如該［H1］~［H5］中任一項之n型GaN結晶，其中載子濃度為1×10¹⁸cm^-3以上、2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上。［H11］如該［H9］或［H10］之n型GaN結晶，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。［H12］如該［H9］~［H11］中任一項之n型GaN結晶，其所含有之最高濃度的施體雜質為Ge。［H13］如該［H11］或［H12］之n型GaN結晶，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［H14］如該［H9］或［H10］之n型GaN結晶，其所含有之最高濃度的施體雜質為Si。［H15］如該［H14］之n型GaN結晶，其中Si以外之施體雜質的總濃度為Si濃度的10 %以下、5 %以下或1 %以下。［H16］如該［H15］之n型GaN結晶，其中載子濃度為Si濃度的90 %以上。［H17］如該［H14］~［H16］中任一項之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。［H18］如該［H1］~［H17］中任一項之n型GaN結晶，其係由以HVPE成長的GaN結晶所構成。［H19］如該［H1］~［H18］中任一項之n型GaN結晶，其係GaN晶圓。［H20］如該［H19］之n型GaN結晶，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下、0.1度以下、或0.08度以下。［H21］一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如該［H19］或［H20］之n型GaN結晶的步驟；及在該所準備之n型GaN結晶之上使一層以上的氮化物半導體層磊晶成長的步驟。［H22］一種磊晶晶圓，其係由如該［H19］或［H20］之n型GaN結晶與在該n型GaN結晶上磊晶成長的一層以上的氮化物半導體層所構成。［H23］一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如該［H19］或［H20］之n型GaN結晶的步驟；及在該所準備之n型GaN結晶之上使一層以上的氮化物半導體層磊晶成長的步驟。［H24］一種雙層GaN晶圓的製造方法，具有：準備如該［H1］~［H8］中任一項之n型GaN結晶的GaN晶圓的步驟；及在該所準備之GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。［H25］如該［H24］之製造方法，其中在該磊晶成長之步驟中，以HVPE使該GaN層成長。［H26］如該［H24］或［H25］之製造方法，其中該GaN層的厚度為500 μm以下。［H27］如該［H24］~［H26］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上或4×10¹⁸cm^-3以上的區域。［H28］如該［H24］~［H27］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。［H29］如該［H24］~［H28］中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意地摻雜有Si。［H30］如該［H24］之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域，係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。［H31］如該［H24］~［H30］中任一項之製造方法，其更具有將該磊晶成長之步驟中所得到的積層體薄化的步驟。［H32］一種塊體GaN結晶的製造方法，具有：準備如該［H1］~［H8］中任一項之n型GaN結晶的GaN晶圓的步驟；及在該所準備之GaN晶圓上使GaN磊晶成長的步驟。[發明之效果]根據較佳的實施態樣之一，可提供一種以HVPE進行成長、且（004）XRD搖擺曲線半值寬度在20 arcsec以下的GaN結晶。Embodiments of the present invention further include the following [H1] to [H32]. [H1] An n-type GaN crystal having two main faces facing opposite directions, one of the two main faces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees relative to the (0001) crystal plane, and having an X-ray abnormal transmission image of at least one 10 mm×10 mm square area, and having an impurity concentration satisfying one or more of the following conditions (a) to (c): (a) Si concentration being not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration being not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration being not more than 1×10¹⁷ atoms/cm³ . [H2] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein an X-ray abnormal transmission image of at least one square area of 15 mm×15 mm is obtained, and wherein the impurity concentration satisfies one or more of the following conditions (a) to (c): (a) Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration is not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration is not more than 1×10¹⁷ atoms/cm³ . [H3] An n-type GaN crystal having two principal surfaces facing opposite directions, one of the two principal surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein an X-ray abnormal transmission image of at least one square area of 20 mm×20 mm is obtained, and wherein the impurity concentration satisfies one or more of the following conditions (a) to (c): (a) Si concentration is not less than 5×10¹⁶ atoms/cm³ ; (b) O concentration is not more than 3×10¹⁶ atoms/cm³ ; (c) H concentration is not more than 1×10¹⁷ atoms/cm³ . [H4] An n-type GaN crystal as described in any one of [H1] to [H3], wherein the impurity concentration satisfies all of the conditions (a) to (c). [H5] An n-type GaN crystal as described in any one of [H1] to [H4], wherein the O concentration is 3×10¹⁶ atoms/cm³ or less, 2×10¹⁶ atoms/cm³ or less, or 1×10¹⁶ atoms/cm³ or less. [H6] An n-type GaN crystal as described in any one of [H1] to [H5], which has at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of 0.04 Ω･cm or more. [H7] An n-type GaN crystal as described in any one of [H1] to [H6], wherein the Si concentration is 5×10¹⁷ atoms/cm³ or less. [H8] The n-type GaN crystal of [H7], wherein the concentration of each impurity other than Si, O and H is 5×10¹⁵ atoms/cm³ or less. [H9] The n-type GaN crystal of any one of [H1] to [H5], having a room temperature resistivity of less than 0.03 Ω･cm, less than 0.02 Ω･cm, less than 0.015 Ω･cm or less than 0.010 Ω･cm. [H10] The n-type GaN crystal of any one of [H1] to [H5], wherein the carrier concentration is 1×10¹⁸ cm^-3 or more, 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [H11] The n-type GaN crystal of [H9] or [H10], wherein the Ge concentration is 1×10¹⁸ atoms/cm³ or more, and the Si concentration is 4×10¹⁷ atoms/cm³ or more. [H12] The n-type GaN crystal of any one of [H9] to [H11], wherein the highest concentration of the donor impurity contained therein is Ge. [H13] The n-type GaN crystal of [H11] or [H12], wherein the concentration of each impurity other than Ge, Si, O and H is 5×10¹⁵ atoms/cm³ or less. [H14] The n-type GaN crystal of [H9] or [H10], wherein the highest concentration of the donor impurity contained therein is Si. [H15] The n-type GaN crystal of [H14], wherein the total concentration of donor impurities other than Si is less than 10%, less than 5%, or less than 1% of the Si concentration. [H16] The n-type GaN crystal of [H15], wherein the carrier concentration is more than 90% of the Si concentration. [H17] The n-type GaN crystal of any one of [H14] to [H16], wherein the concentration of each impurity other than Si, O, and H is less than 5×10¹⁵ atoms/cm^3. [H18] The n-type GaN crystal of any one of [H1] to [H17], which is composed of a GaN crystal grown by HVPE. [H19] The n-type GaN crystal of any one of [H1] to [H18], which is a GaN wafer. [H20] The n-type GaN crystal of [H19], wherein the variation of the x-direction component of the cutting angle on a line extending in the x-direction through the center of the surface and the variation of the y-direction component of the cutting angle on a line extending in the y-direction perpendicular to the x-direction through the center of the surface are respectively less than 0.15 degrees, less than 0.1 degrees, or less than 0.08 degrees within a length range of 40 mm. [H21] A method for manufacturing an epitaxial wafer, which comprises the following steps: preparing an n-type GaN crystal of [H19] or [H20]; and epitaxially growing one or more nitride semiconductor layers on the prepared n-type GaN crystal. [H22] An epitaxial wafer, which is composed of an n-type GaN crystal such as [H19] or [H20] and one or more nitride semiconductor layers epitaxially grown on the n-type GaN crystal. [H23] A method for manufacturing a nitride semiconductor device, which is composed of the following steps: a step of preparing an n-type GaN crystal such as [H19] or [H20]; and a step of epitaxially growing one or more nitride semiconductor layers on the prepared n-type GaN crystal. [H24] A method for manufacturing a double-layer GaN wafer, comprising: a step of preparing a GaN wafer of n-type GaN crystal as described in any one of [H1] to [H8]; and a step of epitaxially growing a GaN layer having a thickness of 20 μm or more on the main surface of the Ga polar side of the prepared GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region having a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more, and the carrier compensation region is a region having a total concentration lower limit of compensation impurities of 2×10¹⁷ atoms/cm³ or more. [H25] The manufacturing method of [H24], wherein in the step of epitaxial growth, the GaN layer is grown by HVPE. [H26] The manufacturing method of [H24] or [H25], wherein the thickness of the GaN layer is 500 μm or less. [H27] The manufacturing method of any one of [H24] to [H26], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region having a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. [H28] The manufacturing method of any one of [H24] to [H27], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge. [H29] The manufacturing method of any one of [H24] to [H28], wherein the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is intentionally doped with Si. [H30] The manufacturing method of [H24], wherein the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the carrier compensation region is 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. [H31] The manufacturing method of any one of [H24] to [H30], further comprising the step of thinning the laminate obtained in the epitaxial growth step. [H32] A method for manufacturing bulk GaN crystals, comprising: preparing a GaN wafer of n-type GaN crystals as described in any one of [H1] to [H8]; and growing GaN epitaxially on the prepared GaN wafer. [Effect of the invention] According to one of the preferred embodiments, a GaN crystal grown by HVPE and having a (004) XRD swing curve half-value width of less than 20 arcsec can be provided.

GaN結晶中，將（0001）結晶面及（000-1）結晶面統稱為c面，將｛10-10｝結晶面稱為m面，並將｛11-20｝結晶面稱為a面。與c面垂直的結晶軸稱為c軸，與m面垂直的結晶軸稱為m軸，與a面垂直的結晶軸稱為a軸。本說明書中，提及結晶軸、結晶面、結晶方位等的情況中，若未特別說明，則係指GaN結晶的結晶軸、結晶面、結晶方位等。六方晶的米勒指數（hkil）具有h＋k＝-i的關係，因此有時亦以3位數表記為（hkl）。例如，將（0004）以3位數表記為（004）。以下適當參照圖式，配合實施態樣說明本發明。In GaN crystals, the (0001) crystal plane and the (000-1) crystal plane are collectively referred to as the c-plane, the {10-10} crystal plane is referred to as the m-plane, and the {11-20} crystal plane is referred to as the a-plane. The crystal axis perpendicular to the c-plane is referred to as the c-axis, the crystal axis perpendicular to the m-plane is referred to as the m-axis, and the crystal axis perpendicular to the a-plane is referred to as the a-axis.In this specification, when the crystal axis, crystal plane, crystal orientation, etc. are mentioned, unless otherwise specified, they refer to the crystal axis, crystal plane, crystal orientation, etc. of the GaN crystal.The Miller index (hkil) of the hexagonal crystal has the relationship of h+k=-i, so it is sometimes expressed as a three-digit number (hkl). For example, (0004) is represented by 3 digits as (004).The present invention is described below with reference to the drawings and embodiments.

1. n型GaN結晶1.1. 形態及尺寸第一圖所示的結晶10係顯示實施態樣之n型GaN結晶的一例。結晶10，具有互相朝向相反方向的2個主面（大面積面）、亦即第一主面11與第二主面12。第一主面11與第二主面12中，任一者為Ga極性，另一者為N極性。第一主面11與第二主面12較佳為互相平行。1. n-type GaN crystal1.1. Morphology and sizeThe crystal 10 shown in the first figure is an example of an n-type GaN crystal showing an implementation mode.The crystal 10 has two main surfaces (large area surfaces) facing in opposite directions, namely, a first main surface 11 and a second main surface 12. One of the first main surface 11 and the second main surface 12 is Ga polarity and the other is N polarity. The first main surface 11 and the second main surface 12 are preferably parallel to each other.

第一主面11為Ga極性且第二主面12為N極性時，第一主面11相對於（0001）結晶面的傾斜為0度以上10度以下。該傾斜可為0.2度以上，又，亦可為小於5度、小於2.5度、小於2度、小於1.5度、小於1度或小於0.5度。第一主面11相對於（0001）結晶面的傾斜，換言之係結晶10的［0001］方向與第一主面11的法線向量所形成的角度。第一主面11為N極性而第二主面12為Ga極性時，第一主面11相對於（000-1）結晶面的傾斜為0度以上10度以下。該傾斜可小於5度、小於2.5度、小於2度、小於1.5度、小於1度或小於0.5度。When the first principal surface 11 is Ga polarity and the second principal surface 12 is N polarity, the inclination of the first principal surface 11 relative to the (0001) crystal plane is greater than 0 degrees and less than 10 degrees. The inclination may be greater than 0.2 degrees, and may also be less than 5 degrees, less than 2.5 degrees, less than 2 degrees, less than 1.5 degrees, less than 1 degree, or less than 0.5 degrees.The inclination of the first principal surface 11 relative to the (0001) crystal plane, in other words, is the angle formed by the [0001] direction of the crystal 10 and the normal vector of the first principal surface 11.When the first principal surface 11 is N polarity and the second principal surface 12 is Ga polarity, the inclination of the first principal surface 11 relative to the (000-1) crystal plane is greater than 0 degrees and less than 10 degrees. The tilt may be less than 5 degrees, less than 2.5 degrees, less than 2 degrees, less than 1.5 degrees, less than 1 degree, or less than 0.5 degrees.

第一主面11及第二主面12的面積較佳係分別為3 cm²以上。結晶10的直徑D_C通常可為20 mm以上、45 mm以上、95 mm以上、或145 mm以上，典型而言為25~27 mm（約1英吋）、50~55 mm（約2英吋）、100~105 mm（約4英吋）、150~155 mm（約6英吋）等。第一主面11及第二主面12的形狀不限定於圓形，亦可變更為正方形、長方形等的四角形、正六角形等、正八角形等的多角形、其他任意的形狀。The area of the first main surface 11 and the second main surface 12 is preferably 3 cm² or more. The diameter_DC of the crystal 10 can usually be 20 mm or more, 45 mm or more, 95 mm or more, or 145 mm or more, typically 25-27 mm (about 1 inch), 50-55 mm (about 2 inches), 100-105 mm (about 4 inches), 150-155 mm (about 6 inches), etc. The shapes of the first main surface 11 and the second main surface 12 are not limited to circles, and can also be changed to quadrilaterals such as squares and rectangles, regular hexagons, regular octagons, etc., polygons, or other arbitrary shapes.

結晶10可為鑄錠或晶圓，除此之外，亦可為在其他GaN結晶上成長的磊晶層或與貼合於支撐基板的膜等。亦即，結晶10可為獨立，亦可為非獨立。結晶10為鑄錠時，其厚度t_C較佳為1.5 mm以上，更佳為2 mm以上，再佳為3 mm以上。結晶10為晶圓時，其厚度t_C可為200 μm以上且小於500 μm、500 μm以上且小於750 μm、750μm 以上且小於1 mm、1 mm以上且小於2 mm等。結晶10為成長於其他GaN結晶上之磊晶層或貼合於支撐基板的膜時，其厚度t_C可為5 μm以上且小於50 μm、50 μm以上且小於100 μm、100 μm以上且小於150 μm、150 μm以上且250 μm以下等。The crystal 10 may be an ingot or a wafer. In addition, it may be an epitaxial layer grown on other GaN crystals or a film attached to a supporting substrate. That is, the crystal 10 may be independent or non-independent. When the crystal 10 is an ingot, its thickness t_C is preferably greater than 1.5 mm, more preferably greater than 2 mm, and even more preferably greater than 3 mm. When the crystal 10 is a wafer, its thickness t_C may be greater than 200 μm and less than 500 μm, greater than 500 μm and less than 750 μm, greater than 750 μm and less than 1 mm, greater than 1 mm and less than 2 mm, etc. When the crystal 10 is an epitaxial layer grown on other GaN crystals or a film bonded to a supporting substrate, its thickness t_C can be greater than 5 μm and less than 50 μm, greater than 50 μm and less than 100 μm, greater than 100 μm and less than 150 μm, greater than 150 μm and less than 250 μm, etc.

1.2. 性質結晶10係由以HVPE成長的GaN所構成。以具備石英反應器的一般HVPE裝置成長的GaN，關於雜質濃度通常滿足選自以下（a）~（c）中的一個以上的條件。（a）Si濃度為5×10¹⁶atoms/cm³以上。（b）O濃度為3×10¹⁶atoms/cm³以下。（c）H濃度為1×10¹⁷atoms/cm³以下。結晶10可滿足全數上述條件（a）~（c）。1.2. Properties Crystal 10 is composed of GaN grown by HVPE. GaN grown by a general HVPE device equipped with a quartz reactor usually satisfies one or more of the following conditions (a) to (c) regarding impurity concentration. (a) Si concentration is 5×10¹⁶ atoms/cm³ or more. (b) O concentration is 3×10¹⁶ atoms/cm³ or less. (c) H concentration is 1×10¹⁷ atoms/cm³ or less. Crystal 10 can satisfy all of the above conditions (a) to (c).

結晶10係含有施體雜質的n型半導體。雖未限定，但在一例中，結晶10的室溫電阻率（室溫下的比電阻（resistivity））可小於0.03 Ω･cm，較佳為小於0.02 Ω･cm，更佳為小於0.015 Ω･cm，再佳為小於0.010 Ω･cm。結晶10可含有的施體雜質，具有Si（矽）、Ge（鍺）等的14族元素與、O（氧）、S（硫）等的16族元素。結晶10所含有之最高濃度的施體雜質，較佳為Si或Ge。Crystal 10 is an n-type semiconductor containing donor impurities. Although not limited, in one example, the room temperature resistivity (specific resistance at room temperature) of crystal 10 may be less than 0.03 Ω･cm, preferably less than 0.02 Ω･cm, more preferably less than 0.015 Ω･cm, and even more preferably less than 0.010 Ω･cm.Crystal 10 may contain donor impurities including Group 14 elements such as Si (silicon) and Ge (germanium) and Group 16 elements such as O (oxygen) and S (sulfur).The donor impurity with the highest concentration contained in crystal 10 is preferably Si or Ge.

一例中，藉由使Si以外之施體雜質的總濃度充分低於Si濃度，可藉由調節Si濃度來控制結晶10的載子濃度。因此較佳係使Si以外之施體雜質的總濃度在Si濃度的10 %以下，更佳為5 %以下，再佳為1 %以下。Si以外之施體雜質的總濃度為Si濃度的10 %以下時，結晶10的載子濃度可為Si濃度的90 %以上。結晶10中添加Ge時，使成長時所使用的載子氣體所包含之H₂之莫耳比較高，雖可有效降低Ge的濃度不均，但會伴隨結晶10的Si濃度成為10¹⁷atoms/cm³的等級以上。In one example, by making the total concentration of donor impurities other than Si sufficiently lower than the Si concentration, the carrier concentration of the crystal 10 can be controlled by adjusting the Si concentration. Therefore, it is preferred that the total concentration of donor impurities other than Si is less than 10% of the Si concentration, more preferably less than 5%, and even more preferably less than 1%. When the total concentration of donor impurities other than Si is less than 10% of the Si concentration, the carrier concentration of the crystal 10 can be more than 90% of the Si concentration. When Ge is added to the crystal 10, the molar ratio of H₂ contained in the carrier gas used during the growth is made higher, which can effectively reduce the concentration unevenness of Ge, but the Si concentration of the crystal 10 will become more than 10¹⁷ atoms/cm³ .

為了充分降低結晶10的電阻率，較佳係使結晶10在室溫中的載子濃度為1×10¹⁸cm^-3以上，再佳為2×10¹⁸cm^-3以上。該載子濃度可為3×10¹⁸cm^-3以上，進一步可為4×10¹⁸cm^-3以上。從電特性的觀點來看，該載子濃度並無特別的上限，但為了不導致結晶10的生產性變差，可將該載子濃度設定於1×10¹⁹cm^-3以下，亦可設定為8×10¹⁸cm^-3以下，進一步可為5×10¹⁸cm^-3以下。這是因為高濃度的摻雜會提高異常成長的發生頻率。In order to sufficiently reduce the resistivity of the crystal 10, it is preferred that the carrier concentration of the crystal 10 at room temperature is 1×10¹⁸ cm^-3 or more, and more preferably 2×10¹⁸ cm^-3 or more. The carrier concentration may be 3×10¹⁸ cm^-3 or more, and further may be 4×10¹⁸ cm^-3 or more. From the perspective of electrical properties, there is no particular upper limit to the carrier concentration, but in order not to deteriorate the productivity of the crystal 10, the carrier concentration may be set to 1×10¹⁹ cm^-3 or less, and may also be set to 8×10¹⁸ cm^-3 or less, and further may be set to 5×10¹⁸ cm^-3 or less. This is because high concentrations of doping increase the frequency of abnormal growth.

1.3. 結晶品質結晶10的品質，可以使用CuKα1放射的ω掃描所測量之（004）XRD搖擺曲線FWHM為指標來進行評估。結晶品質越好，（004）XRD搖擺曲線FWHM越窄。（004）XRD搖擺曲線測量中，以電壓45kV、電流40mA使X射線管球運作，將使用Ge（440）4結晶對稱單色儀進行單色化的CuK_α射線入射第一主面11。並未特別限定X射線從何方向射入第一主面11，例如，可使X射線的入射面與a軸垂直。1.3. Crystal quality The quality of the crystal 10 can be evaluated using the (004) XRD swing curve FWHM measured by ω scanning of CuKα1 radiation as an indicator. The better the crystal quality, the narrower the (004) XRD swing curve FWHM. In the (004) XRD swing curve measurement, the X-ray tube was operated at a voltage of 45 kV and a current of 40 mA, and CuK_α rays monochromated using a Ge (440) 4 crystal symmetry monochromator were incident on the first main surface 11. There is no particular limitation on the direction from which the X-rays are incident on the first main surface 11. For example, the incident plane of the X-rays can be perpendicular to the a-axis.

X射線的光束尺寸，在使入射角（反射面與X射線所形成的角度）為90°時，亦即使X射線垂直入射作為反射面的（004）面時，第一主面11上的照射區域之尺寸，針對與ω軸平行之方向係設定為5 mm，針對與ω軸垂直之方向係設定為1 mm。ω軸係指在搖擺曲線測量中試片的旋轉軸。在將X射線的光束尺寸如此設定時，GaN的（004）XRD搖擺曲線測量中，ω約為36.5°，因此第一主面11上的照射區域的尺寸約為1.7×5 mm²。如此所測量之（004）XRD搖擺曲線FWHM可小於20 arcsec，進一步可小於18 arcsec，進一步可小於16 arcsec，進一步可小於14 arcsec，進一步可小於12 arcsec。When the incident angle (the angle between the reflection surface and the X-ray) is 90°, that is, when the X-ray is incident perpendicularly on the (004) surface as the reflection surface, the size of the irradiation area on the first principal surface 11 is set to 5 mm in the direction parallel to the ω axis and 1 mm in the direction perpendicular to the ω axis. The ω axis refers to the rotation axis of the specimen in the wobble curve measurement. When the X-ray beam size is set in this way, in the (004) XRD wobble curve measurement of GaN, ω is about 36.5°, so the size of the irradiation area on the first principal surface 11 is about 1.7×5 mm² . The FWHM of the (004) XRD swing curve measured in this way may be less than 20 arcsec, further may be less than 18 arcsec, further may be less than 16 arcsec, further may be less than 14 arcsec, further may be less than 12 arcsec.

第一主面11的直徑超過40 mm時，如第二圖所示，藉由在第一主面11上，以沿著1條線L於長度40 mm中每隔1 mm即以上述條件進行ω掃描，可得到在該線L上以1 mm間距並列40個測量點P_M的（004）XRD搖擺曲線。此情況中，各測量點P_M的ω掃描中，使ω軸與線L垂直。亦即，以使X射線入射面與線L平行的方式，將X射線入射結晶10。When the diameter of the first principal surface 11 exceeds 40 mm, as shown in the second figure, by performing ω scanning at intervals of 1 mm along a line L in a length of 40 mm on the first principal surface 11 under the above conditions, a (004) XRD swing curve of 40 measurement points_PM arranged at intervals of 1 mm on the line L can be obtained. In this case, in the ω scanning of each measurement point_PM , the ω axis is made perpendicular to the line L. That is, the X-ray is incident on the crystal 10 in such a way that the X-ray incident plane is parallel to the line L.

較佳例中，在第一主面11上沿著至少1條線進行此測量時，在所有測量點之間的（004）XRD搖擺曲線FWHM的最大值可在20 arcsec以下。該所有測量點之間的（004）XRD搖擺曲線FWHM的平均值，可為18 arcsec以下，進一步可為16 arcsec以下，進一步可為14 arcsec以下，進一步可為12 arcsec，進一步可為10 arcsec以下。In a preferred embodiment, when the measurement is performed along at least one line on the first main surface 11, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points can be less than 20 arcsec.The average value of the FWHM of the (004) XRD swing curve between all measurement points can be less than 18 arcsec, further less than 16 arcsec, further less than 14 arcsec, further less than 12 arcsec, and further less than 10 arcsec.

第一主面11的直徑超過40 mm時，再者，在第一主面11上，分別沿著如第三圖例示的互相垂直的2條線L₁及L₂，於長度40 mm中每隔1 mm即以上述條件進行ω掃描，藉此可在各線L₁、L₂上得到以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。此情況中，在線L₁上的各測量點之中的ω掃描中，使ω軸與線L₁垂直，而在線L₂上的各測量點中的ω掃描中，使ω軸與線L₂垂直。When the diameter of the first main surface 11 exceeds 40 mm, ω scanning is performed at intervals of 1 mm along two mutually perpendicular lines_L1 and_L2 as shown in the third figure on the first main surface 11 under the above conditions within a length of 40 mm, thereby obtaining (004) XRD swing curves of 40 measurement points arranged at 1 mm intervals on each line_L1 and_L2 . In this case, in the ω scanning at each measurement point on the line_L1 , the ω axis is made perpendicular to the line_L1 , and in the ω scanning at each measurement point on the line_L2 , the ω axis is made perpendicular to the line_L2 .

較佳例中，在第一主面11上，分別沿著至少2條互相垂直的線進行此測量時，在各線上的所有測量點之間的（004）XRD搖擺曲線FWHM的最大值會在20 arcsec以下。亦即，該2條線中的一條上的40個測量點之間的最大值與另一條上的40個測量點之間的最大值皆會在20 arcsec以下。各線上的所有測量點之間的（004）XRD搖擺曲線FWHM的平均值可為18 arcsec以下，進一步可為16 arcsec以下，進一步可為14 arcsec以下，進一步可為12 arcsec以下，進一步可為10 arcsec以下。In a preferred example, when the measurement is performed along at least two mutually perpendicular lines on the first main surface 11, the maximum value of the FWHM of the (004) XRD swing curve between all the measurement points on each line is less than 20 arcsec. That is, the maximum value between 40 measurement points on one of the two lines and the maximum value between 40 measurement points on the other line are both less than 20 arcsec.The average value of the FWHM of the (004) XRD swing curve between all the measurement points on each line can be less than 18 arcsec, further less than 16 arcsec, further less than 14 arcsec, further less than 12 arcsec, and further less than 10 arcsec.

在以蘭氏法（Lang's method）進行的X射線形貌分析中，從結晶10可得到至少一個10 mm×10 mm的正方形區域的X射線異常穿透像。蘭氏法中，在板狀試片中一側的主面側配置X射線源，而在另一側的主面側配置X射線檢測器。X射線的異常穿透亦被稱為博曼效應（Borrmann effect），此現象係使X射線穿透通常因吸收現象而無法穿透之厚度的結晶。例如，在使用MoKα（波長0.71073Å）作為X射線源的X射線形貌分析中，從厚度344 μm的GaN結晶得到穿透像的情況，即為異常穿透像。這是因為在X射線源為MoKα的情況下，GaN的吸收係數μ為290.40 cm^-1，而在晶圓的厚度t為344 μm時，μ･t＝10.0，此時若無異常穿透，則在μ･t≧10的條件下無法得到穿透像。在結晶完整性低時無法觀察到異常穿透像，因此能夠在X射線形貌分析中得到異常穿透像的GaN結晶可說是其品質良好。較佳係從結晶10得到至少一個15 mm×15 mm的正方形區域的X射線異常穿透像，更佳係得到至少一個20 mm×20 mm的正方形區域的X射線異常穿透像。In the X-ray morphology analysis performed by Lang's method, an X-ray abnormal transmission image of at least one square area of 10 mm×10 mm can be obtained from the crystal 10. In the Lang's method, an X-ray source is arranged on the main surface side of one side of the plate-like specimen, and an X-ray detector is arranged on the main surface side of the other side. The abnormal transmission of X-rays is also called the Borrmann effect, which is a phenomenon that allows X-rays to penetrate a crystal of a thickness that cannot be penetrated normally due to absorption phenomena. For example, in the X-ray morphology analysis using MoKα (wavelength 0.71073Å) as the X-ray source, when a transmission image is obtained from a GaN crystal with a thickness of 344 μm, it is an abnormal transmission image. This is because when the X-ray source is MoKα, the absorption coefficient μ of GaN is 290.40 cm^-1 , and when the wafer thickness t is 344 μm, μ･t＝10.0. If there is no abnormal penetration at this time, no transmission image can be obtained under the condition of μ･t≧10. Abnormal transmission images cannot be observed when the crystal integrity is low, so GaN crystals that can obtain abnormal transmission images in X-ray morphology analysis can be said to have good quality. It is preferred to obtain at least one 15 mm×15 mm square X-ray abnormal transmission image from crystal 10, and it is more preferred to obtain at least one 20 mm×20 mm square X-ray abnormal transmission image.

2. GaN晶圓本說明書中，將來自（0001）結晶面或（000-1）結晶面的切割角在10度以下的GaN晶圓稱為c面GaN晶圓。2. GaN wafersIn this manual, GaN wafers with a cutting angle of less than 10 degrees from the (0001) crystal plane or the (000-1) crystal plane are called c-plane GaN wafers.

2.1. 形態及尺寸第四圖所示的晶圓20係顯示實施態樣之GaN晶圓的一例。晶圓20為c面GaN晶圓，互相朝向相反方向的其2個主面（大面積面）、亦即第一主面21與第二主面22，一邊為Ga極性，另一邊為N極性。Ga極性側的主面有時被稱為Ga極性面，又N極性側的主面有時被稱為N極性面。第一主面21為Ga極性時，第一主面21相對於（0001）結晶面的傾斜為0度以上10度以下。該傾斜可為0.2度以上，又可為小於5度、小於2.5度、小於1.5度、小於1度或小於0.5度。第一主面21為N極性時，第一主面21相對於（000-1）結晶面的傾斜為0度以上10度以下。該傾斜亦可小於5度、小於2.5度、小於1.5度、小於1度或小於0.5度。第一主面21與第二主面22較佳為互相平行。2.1. Shape and sizeThe wafer 20 shown in FIG. 4 is an example of a GaN wafer showing an implementation.The wafer 20 is a c-plane GaN wafer, and its two main surfaces (large area surfaces) facing opposite directions, namely the first main surface 21 and the second main surface 22, are Ga polarity on one side and N polarity on the other side. The main surface on the Ga polarity side is sometimes called the Ga polarity surface, and the main surface on the N polarity side is sometimes called the N polarity surface.When the first main surface 21 is Ga polarity, the inclination of the first main surface 21 relative to the (0001) crystal plane is greater than 0 degrees and less than 10 degrees. The inclination can be greater than 0.2 degrees, and can also be less than 5 degrees, less than 2.5 degrees, less than 1.5 degrees, less than 1 degree, or less than 0.5 degrees.When the first main surface 21 is N-polar, the inclination of the first main surface 21 relative to the (000-1) crystal plane is greater than 0 degrees and less than 10 degrees. The inclination may also be less than 5 degrees, less than 2.5 degrees, less than 1.5 degrees, less than 1 degree or less than 0.5 degrees.The first main surface 21 and the second main surface 22 are preferably parallel to each other.

晶圓20的直徑D_W通常可為45 mm以上、95 mm以上、或145 mm以上，典型為50~55 mm（約2英吋）、100~105 mm（約4英吋）、150~155 mm（約6英吋）等。晶圓20的厚度t_W，係因應直徑D_W而以晶圓20可獨立且可處理的方式設計。例如晶圓20的直徑D_W約2英吋時，厚度t_W較佳為250~500 μm，更佳為300~450 μm，晶圓20的直徑D_W約4英吋時，厚度t_W較佳為400~800 μm，更佳為500~650 μm。晶圓20的直徑D_W約6英吋時，厚度t_W較佳為500~850 μm，更佳為600~750 μm。The diameter D_W of the wafer 20 may generally be greater than 45 mm, greater than 95 mm, or greater than 145 mm, and is typically 50-55 mm (approximately 2 inches), 100-105 mm (approximately 4 inches), 150-155 mm (approximately 6 inches), etc. The thickness t_W of the wafer 20 is designed in a manner that the wafer 20 can be independently and processable according to the diameter D_W. For example, when the diameter D_W of the wafer 20 is approximately 2 inches, the thickness t_W is preferably 250-500 μm, more preferably 300-450 μm. When the diameter D_W of the wafer 20 is approximately 4 inches, the thickness t_W is preferably 400-800 μm, more preferably 500-650 μm. When the diameter D_W of the wafer 20 is about 6 inches, the thickness t_W is preferably 500-850 μm, more preferably 600-750 μm.

晶圓20的切割角可分解成x方向分量與y方向向量，其係在第一主面21內互相正交的2方向的向量。若參照第十五圖說明，在使第一主面21的法線方向為z方向、使與c軸平行之向量為向量Vc時，晶圓20的切割角等於向量Vc從z軸傾斜的角度θ。該向量Vc，可分解成x方向向量的向量Vc_x與y方向成分的向量Vc_y。xz平面上的向量Vc的正投影為向量Vc_x，yz平面上的向量Vc的正投影為向量Vc_y。在以此方式分解向量Vc時，向量Vc_x從z軸傾斜的角度為切割角θ的x方向分量θ_x，向量Vc_y從z軸傾斜的角度為切割角θ的y軸方向分量θ_y。The cutting angle of the wafer 20 can be decomposed into an x-direction component and a y-direction vector, which are two vectors orthogonal to each other in the first main surface 21. Referring to FIG. 15, when the normal direction of the first main surface 21 is the z-direction and the vector parallel to the c-axis is the vector Vc, the cutting angle of the wafer 20 is equal to the angle θ at which the vector Vc is tilted from the z-axis. The vector Vc can be decomposed into a vector Vc_x of the x-direction vector and a vector Vc_y of the y-direction component. The orthogonal projection of the vector Vc on the xz plane is the vector Vc_x , and the orthogonal projection of the vector Vc on the yz plane is the vector Vc_y . When the vector Vc is decomposed in this way, the angle at which the vector Vc_x is tilted from the z-axis is the x-direction component θ_x of the cutting angle θ, and the angle at which the vector Vc_y is tilted from the z-axis is the y-direction component θ_y of the cutting angle θ.

晶圓20中，切割角之x方向分量在通過第一主面21之中心而在x方向上延伸之線上的變動幅度與切割角之y方向分量在通過第一主面21之中心而在y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下，較佳為0.1度以下，更佳為0.08度以下。在該評估中，可將俯視晶圓20時與外周的距離小於5 mm的部分排除。變動幅度係指最大值與最小值的差，例如變動幅度在0.15度以下，換言之，係相較於中間值的變動在±0.075度以內。x方向可與a面之一平行，此時y方向與m面之一平行。In the wafer 20, the variation range of the x-direction component of the cutting angle on the line extending in the x-direction through the center of the first main surface 21 and the variation range of the y-direction component of the cutting angle on the line extending in the y-direction through the center of the first main surface 21 are respectively less than 0.15 degrees, preferably less than 0.1 degrees, and more preferably less than 0.08 degrees within a length range of 40 mm. In this evaluation, the portion less than 5 mm from the periphery when looking down at the wafer 20 can be excluded.The variation range refers to the difference between the maximum value and the minimum value. For example, the variation range is less than 0.15 degrees, in other words, the variation relative to the median value is within ±0.075 degrees.The x direction can be parallel to one of the a surfaces, and the y direction is parallel to one of the m surfaces.

晶圓20的第一主面21，例如在使用晶圓20作為基板製造氮化物半導體裝置時，預定用於氮化物半導體之磊晶成長的主面即為「表面」。第一主面21進行鏡面拋光，其以AFM測量的方均根（RMS）粗糙度，在測量範圍2 μm×2 μm中，較佳為小於2 nm，亦可小於1 nm或小於0.5 nm。第二主面22為「背面」，其亦可進行鏡面拋光，亦可進行消光加工。The first main surface 21 of the wafer 20 is the main surface intended for epitaxial growth of nitride semiconductors when the wafer 20 is used as a substrate to manufacture nitride semiconductor devices. The first main surface 21 is mirror polished, and its root mean square (RMS) roughness measured by AFM is preferably less than 2 nm in the measurement range of 2 μm×2 μm, and may be less than 1 nm or less than 0.5 nm.The second main surface 22 is the "back side", which may also be mirror polished or matte processed.

晶圓20的邊緣亦可進行倒角。亦可將表示結晶方位的晶向平邊或缺口、使表面與背面容易辨識的指標、平邊等因應需求的各種標記施予晶圓20。晶圓20的主面雖為圓形，但並不限於圓形，亦可變更為正方形、長方形、六角形、八角形、其他任意的形狀。The edge of the wafer 20 may also be chamfered.Various markings may be applied to the wafer 20 in response to needs, such as a flat edge or notch indicating the crystal orientation, an indicator to make the front and back surfaces easily distinguishable, and a flat edge.Although the main surface of the wafer 20 is circular, it is not limited to a circular shape and may be changed to a square, rectangle, hexagon, octagon, or any other arbitrary shape.

2.2. 性質晶圓20係由以HVPE成長的GaN結晶所構成。以具備石英反應器的一般HVPE裝置成長的GaN，關於雜質濃度，通常滿足選自以下（a）~（c）中的一個以上的條件。（a）Si濃度為5×10¹⁶atoms/cm³以上。（b）O濃度為3×10¹⁶atoms/cm³以下。（c）H濃度為1×10¹⁷atoms/cm³以下。晶圓20可滿足全數上述條件（a）~（c）。2.2. Properties Wafer 20 is composed of GaN crystals grown by HVPE. GaN grown by a general HVPE device with a quartz reactor usually satisfies one or more of the following conditions (a) to (c) regarding impurity concentration. (a) Si concentration is 5×10¹⁶ atoms/cm³ or more. (b) O concentration is 3×10¹⁶ atoms/cm³ or less. (c) H concentration is 1×10¹⁷ atoms/cm³ or less. Wafer 20 can satisfy all of the above conditions (a) to (c).

以下敘述作為參考，以HVPE成長的GaN，在紅外吸收光譜的3150~3250 cm^-1的範圍中並未確認到吸收係數超過0.5 cm^-1的吸收峰值，從此點可分辨其與以氨熱法成長的GaN。該紅外吸收峰值，與以氨熱法成長的GaN高濃度地含有鎵空孔相關［S. Suihkonen, et al., Applied Physics Letters 108, 202105 (2016); W. Jiang, et al., Applied Physics Express 10, 075506 (2017)］。The following description is for reference. In the infrared absorption spectrum of GaN grown by HVPE, no absorption peak with an absorption coefficient exceeding 0.5 cm^-1 was confirmed in the range of 3150~3250 cm^-1 , which can be distinguished from GaN grown by ammonothermal method. This infrared absorption peak is related to the high concentration of gallium vacancies in GaN grown by ammonothermal method [S. Suihkonen, et al., Applied Physics Letters 108, 202105 (2016); W. Jiang, et al., Applied Physics Express 10, 075506 (2017)].

晶圓20的蓄意摻雜可因應需求任意進行。因此，在一例中，亦可僅以非蓄意摻雜的GaN（UID-GaN；un-intentionally doped GaN）形成晶圓20。因為非蓄意摻雜的施體雜質與不可避免地產生氮空孔，因此UID-GaN的導電型為n型。UID-GaN中，Si濃度為5×10¹⁷atoms/cm³以下、O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下，除了Si、O及H以外，各雜質的濃度可為5×10¹⁵atoms/cm³以下。UID-GaN中，載子濃度可小於5×10¹⁷cm^-3，且室溫電阻率可為0.04 Ω･cm以上。The intentional doping of the wafer 20 can be performed arbitrarily according to the needs. Therefore, in one example, the wafer 20 can also be formed with only unintentionally doped GaN (UID-GaN; un-intentionally doped GaN). Because the unintentionally doped donor impurities and nitrogen vacancies are inevitably generated, the conductivity type of UID-GaN is n-type. In UID-GaN, the Si concentration is less than 5×10¹⁷ atoms/cm³ , the O concentration is less than 3×10¹⁶ atoms/cm³ , less than 2×10¹⁶ atoms/cm³ , or less than 1×10¹⁶ atoms/cm³ , and the concentration of each impurity except Si, O and H can be less than 5×10¹⁵ atoms/cm³ . In UID-GaN, the carrier concentration can be less than 5×10¹⁷ cm^-3 , and the room temperature resistivity can be above 0.04 Ω･cm.

在一例中，藉由蓄意地摻雜來降低晶圓20的室溫電阻率，可使其小於0.03Ω･cm，進一步可小於0.02Ω･cm，進一步可小於0.015Ω･cm，進一步可小於0.010Ω･cm。為了充分降低電阻率，較佳係使晶圓20在室溫中的載子濃度在1×10¹⁸cm^-3以上，再佳為2×10¹⁸cm^-3以上。該載子濃度可為3×10¹⁸cm^-3以上，進一步可為4×10¹⁸cm^-3以上。從電特性的觀點來看，該載子濃度並無特別的上限，但為了不使晶圓20的生產性變差，可將該載子濃度設為1×10¹⁹cm^-3以下，亦可設為8×10¹⁸cm^-3以下，進一步可設為5×10¹⁸cm^-3以下。這是因為高濃度的摻雜會提高GaN結晶異常成長的發生頻率。In one example, the room temperature resistivity of the wafer 20 can be reduced to less than 0.03Ω·cm, further less than 0.02Ω·cm, further less than 0.015Ω·cm, and further less than 0.010Ω·cm by intentionally doping. In order to sufficiently reduce the resistivity, it is preferred that the carrier concentration of the wafer 20 at room temperature is greater than 1×10¹⁸ cm^-3 , and more preferably greater than 2×10¹⁸ cm^-3 . The carrier concentration can be greater than 3×10¹⁸ cm^-3 , and further can be greater than 4×10¹⁸ cm^-3 . From the perspective of electrical characteristics, there is no particular upper limit for the carrier concentration, but in order not to deteriorate the productivity of the wafer 20, the carrier concentration can be set to less than 1×10¹⁹ cm^-3 , or less than 8×10¹⁸ cm^-3 , or further less than 5×10¹⁸ cm^-3 . This is because high concentrations of doping increase the frequency of abnormal growth of GaN crystals.

為了降低電阻率，晶圓20中添加的摻雜物，較佳為施體雜質，因此藉由摻雜而低電阻化時的晶圓20的導電型較佳為n型。這是因為，一般而言相較於受體雜質，施體雜質呈現較高的活性化率。活性化率，係指在經摻雜的GaN中，載子濃度相對於摻雜物濃度的比例。可作為施體雜質使用的元素，具有Si（矽）、Ge（鍺）等的14族元素與、O（氧）、S（硫）等的16族元素。In order to reduce the resistivity, the dopant added to the wafer 20 is preferably a donor dopant, so the conductivity type of the wafer 20 when the resistance is reduced by doping is preferably n-type. This is because, generally speaking, donor dopants have a higher activation rate than acceptor dopants. The activation rate refers to the ratio of the carrier concentration to the dopant concentration in the doped GaN.The elements that can be used as donor dopants include 14 group elements such as Si (silicon) and Ge (germanium) and 16 group elements such as O (oxygen) and S (sulfur).

在摻雜施體雜質時，晶圓20所含有之最高濃度的施體雜質較佳為Si或Ge，主要的2個理由如下。第一，Si與Ge係具有與O相同程度之高活性化率的施體雜質。第二，為了得到高度摻雜O的GaN而需要進行一面成長（facet growth），相對於此，高度摻雜Si或Ge的GaN可藉由c面成長而得。When doping with donor impurities, the donor impurity with the highest concentration contained in the wafer 20 is preferably Si or Ge, mainly for the following two reasons.First, Si and Ge are donor impurities with a high activation rate similar to that of O.Second, in order to obtain GaN highly doped with O, facet growth is required. In contrast, GaN highly doped with Si or Ge can be obtained by c-face growth.

一面成長，係以使成長表面上形成大量凹槽的方式使［0001］配向的GaN膜成長的技法。相對於此，以使成長表面平坦的方式使該GaN膜成長的方法則稱為c面成長。因為線差排具有集中在凹槽底部的性質，因此以一面成長所形成的GaN膜中，線差排的分布變得不均勻。氮化物半導體裝置的製造者通常不傾向從這種GaN膜裁切出來的c面GaN晶圓。（004）XRD搖擺曲線FWHM在20 arcsec以下的GaN結晶，其線差排的密度低，因此在以適當條件使其進行c面成長時，成長表面平坦且無凸起，而能夠得到極佳的表面形態。Si與Ge可說是能夠發揮此特徵的施體雜質。One-sided growth is a technique for growing a [0001] oriented GaN film in such a way that a large number of grooves are formed on the growth surface. In contrast, the method of growing the GaN film in such a way that the growth surface is flat is called c-plane growth.Since the line dislocations have the property of concentrating at the bottom of the grooves, the distribution of the line dislocations in the GaN film formed by one-sided growth becomes uneven. Manufacturers of nitride semiconductor devices generally do not tend to cut c-plane GaN wafers from such GaN films.GaN crystals with a (004) XRD wobble curve FWHM of less than 20 arcsec have a low line dislocation density. Therefore, when they are grown on the c-plane under appropriate conditions, the growth surface is flat and has no protrusions, and an excellent surface morphology can be obtained. Si and Ge can be said to be donor impurities that can exert this characteristic.

較佳的一例中，藉由使Si以外之施體雜質的總濃度充分低於Si濃度，可藉由調節Si濃度來控制晶圓20的載子濃度。因此，較佳係使Si以外之施體雜質的總濃度在Si濃度的10 %以下，進一步可為5 %以下，進一步可為1 %以下。Si以外之施體雜質的總濃度為Si濃度的 10%以下時，晶圓20的載子濃度可為Si濃度的90 %以上。在晶圓20中蓄意地添加Ge時，使成長時所用的載子氣體所包含之H₂之莫耳比較高，雖可有效降低Ge的濃度不均，但會伴隨晶圓20的Si濃度，即使在非蓄意地添加Si時，亦會成為10¹⁷atoms/cm³的等級以上。In a preferred example, by making the total concentration of donor impurities other than Si sufficiently lower than the Si concentration, the carrier concentration of the wafer 20 can be controlled by adjusting the Si concentration. Therefore, it is preferred that the total concentration of donor impurities other than Si is less than 10% of the Si concentration, further less than 5%, and further less than 1%. When the total concentration of donor impurities other than Si is less than 10% of the Si concentration, the carrier concentration of the wafer 20 can be more than 90% of the Si concentration. When Ge is intentionally added to the wafer 20, the molar ratio of H₂ contained in the carrier gas used in the growth is relatively high. Although this can effectively reduce the concentration unevenness of Ge, it will be accompanied by the Si concentration of the wafer 20, which will become above the level of 10¹⁷ atoms/cm³ even when Si is not intentionally added.

一態樣中，亦可僅對於晶圓20的一部分進行蓄意摻雜。第五圖所示的例子中，晶圓20，在Ga極性的第一主面21側具有蓄意摻雜的GaN（ID-GaN；intentionally doped GaN）所構成的第一區域R₁，在N極性的第二主面22側具有UID-GaN所構成的第二區域R₂。相較於第二區域R₂，第一區域R₁具有較高的載子濃度與較低的電阻率。第一區域R₁與第二區域R₂之間，可設置中間區域（圖中未顯示），其載子濃度在該等2個區域之間。該中間區域中，載子濃度可從N極性側朝向Ga極性側連續性或階段性增加。In one embodiment, only a portion of the wafer 20 may be intentionally doped. In the example shown in FIG. 5, the wafer 20 has a first region R₁ composed of intentionally doped GaN (ID-GaN; intentionally doped GaN) on the Ga-polar first main surface 21 side, and a second region R 2 composed of UID-GaN on the N-polar second main surface₂₂ side. Compared with the second region R₂ , the first region R₁ has a higher carrier concentration and a lower resistivity. Between the first region R₁ and the second region R₂ , an intermediate region (not shown in the figure) may be provided, and its carrier concentration is between the two regions. In the middle region, the carrier concentration may increase continuously or stepwise from the N-polarity side toward the Ga-polarity side.

第一區域R₁的厚度t₁，可為例如5 μm以上且小於50 μm、50 μm以上且小於100 μm、100 μm以上且小於150 μm、150μm以上且小於250 μm以下等。第一區域R₁與第二區域R₂之間，亦可存在再成長界面。亦即，第五圖所示的晶圓20，可經由下述步驟來製造：在使UID-GaN所構成的c面GaN晶圓完成後，於該c面GaN晶圓的Ga極性側主面上以HVPE使ID-GaN層成長。The thickness t₁ of the first region R₁ may be, for example, 5 μm or more and less than 50 μm, 50 μm or more and less than 100 μm, 100 μm or more and less than 150 μm, 150 μm or more and less than 250 μm, etc. A re-growth interface may also exist between the first region R₁ and the second region R_2. That is, the wafer 20 shown in FIG. 5 may be manufactured by the following steps: after a c-plane GaN wafer composed of UID-GaN is completed, an ID-GaN layer is grown on the Ga polar side main surface of the c-plane GaN wafer by HVPE.

第五圖所示的晶圓20中，第一區域R₁中的室溫電阻率可小於0.03 Ω･cm、小於0.02 Ω･cm、小於0.015 Ω･cm，或小於0.010 Ω･cm。第一區域R₁在室溫下的載子濃度，較佳為1×10¹⁸cm^-3以上，更佳為2×10¹⁸cm^-3以上，亦可為3×10¹⁸cm^-3以上，進一步可為4×10¹⁸cm^-3以上。第一區域R₁所含有的蓄意摻雜物，較佳為施體雜質，此時第一區域R₁所含有之最高濃度的施體雜質為Si或Ge。較佳例之中，第一區域R₁中，可使Si以外之施體雜質的總濃度為Si濃度的10 %以下，進一步可為5 %以下，進一步可為1 %以下。第二區域R₂中，Si濃度為5×10¹⁷atoms/cm³以下，O濃度為3×10¹⁶atoms/cm³以下、2×10¹⁶atoms/cm³以下或1×10¹⁶atoms/cm³以下，除了Si、O及H以外，各雜質的濃度可為5×10¹⁵atoms/cm³以下。第二區域R₂中，載子濃度可小於5×10¹⁷，且室溫電阻率可為0.04 Ω･cm以上。2.3. 結晶品質In the wafer 20 shown in FIG. 5 , the room temperature resistivity in the first region R₁ may be less than 0.03 Ω･cm, less than 0.02 Ω･cm, less than 0.015 Ω･cm, or less than 0.010 Ω･cm. The carrier concentration of the first region R₁ at room temperature is preferably 1×10¹⁸ cm^-3 or more, more preferably 2×10¹⁸ cm^-3 or more, and may be 3×10¹⁸ cm^-3 or more, and further may be 4×10¹⁸ cm^-3 or more. The intentional dopant contained in the first region R₁ is preferably a donor impurity, and the highest concentration of the donor impurity contained in the first region R₁ is Si or Ge. In a preferred example, in the first region_R1 , the total concentration of donor impurities other than Si can be made less than 10% of the Si concentration, further less than 5%, and further less than 1%. In the second region_R2 , the Si concentration is less than 5×¹⁰¹⁷ atoms/^cm3 , the O concentration is less than 3×¹⁰¹⁶ atoms/^cm3 , less than 2×¹⁰¹⁶ atoms/^cm3 , or less than 1×¹⁰¹⁶ atoms/^cm3 , and the concentration of each impurity except Si, O and H can be less than 5×¹⁰¹⁵ atoms/^cm3 . In the second region_R2 , the carrier concentration can be less than 5×¹⁰¹⁷ , and the room temperature resistivity can be more than 0.04 Ω･cm. 2.3. Crystal quality

晶圓20的結晶品質，可以藉由使用CuKα₁放射的ω掃描測量的（004）XRD搖擺曲線FWHM作為指標而進行評估。結晶品質越好，則（004）XRD搖擺曲線FWHM越窄。（004）XRD搖擺曲線測量中，以電壓45kV、電流40mA使X射線管球運作，將使用Ge（440）4結晶對稱單色儀而單色化的CuK_α線入射第一主面21。The crystal quality of the wafer 20 can be evaluated by using the (004) XRD swing curve FWHM measured by ω scanning using CuKα₁ radiation as an indicator. The better the crystal quality, the narrower the (004) XRD swing curve FWHM. In the (004) XRD swing curve measurement, the X-ray tube was operated at a voltage of 45 kV and a current of 40 mA, and CuK_α rays monochromated using a Ge (440) 4 crystal symmetric monochromator were incident on the first main surface 21.

X射線的光束尺寸，在使入射角（反射面與X射線形成之角度）為90°時，亦即使X射線垂直入射作為反射面的（004）面時，第一主面21上的照射區域的尺寸，針對與ω軸平行之方向可設為5 mm，針對與ω軸垂直的方向可設為1 mm。ω軸係搖擺曲線測量之中試片的旋轉軸。在如此設定X射線之光束尺寸時，GaN的（004）XRD搖擺曲線測量中ω約為36.5°，第一主面21上的照射面積約為1.7×5 mm²。When the incident angle (the angle between the reflection surface and the X-ray) is 90°, that is, when the X-ray is incident perpendicularly on the (004) surface as the reflection surface, the size of the irradiation area on the first principal surface 21 can be set to 5 mm in the direction parallel to the ω axis and 1 mm in the direction perpendicular to the ω axis. The ω axis is the rotation axis of the specimen in the wobble curve measurement. When the X-ray beam size is set in this way, ω is about 36.5° in the (004) XRD wobble curve measurement of GaN, and the irradiation area on the first principal surface 21 is about 1.7×5 mm² .

如第六圖所示，在晶圓20的第一主面21上，沿著1條線L於長度40 mm中每隔1 mm即進行ω掃描，藉此可得到在該線L上以1 mm間距排列的40個測量點P_M的（004）XRD搖擺曲線。在各測量點P_M的ω掃描中，使ω軸與線L垂直。換言之，以使X射線入射面與線L平行的方式，使X射線入射晶圓20。As shown in FIG. 6, on the first main surface 21 of the wafer 20, ω scanning is performed every 1 mm along a line L with a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points_PM arranged at a pitch of 1 mm on the line L. In the ω scanning of each measurement point_PM , the ω axis is made perpendicular to the line L. In other words, the X-ray is made incident on the wafer 20 in such a way that the X-ray incident plane is parallel to the line L.

晶圓20中，在第一主面21上沿著至少1條線進行此測量時，在所有測量點之間的（004）XRD搖擺曲線FWHM的最大值在20 arcsec以下。該所有測量點之間的（004）XRD搖擺曲線FWHM的平均值可為18 arcsec以下，進一步可為16 arcsec以下，進一步可為14 arcsec以下，進一步可為12 arcsec以下，進一步可為10 arcsec以下。In the wafer 20, when this measurement is performed along at least one line on the first main surface 21, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec.The average value of the FWHM of the (004) XRD swing curve between all measurement points can be less than 18 arcsec, further less than 16 arcsec, further less than 14 arcsec, further less than 12 arcsec, and further less than 10 arcsec.

再者，晶圓20的第一主面21上，分別沿著如第七圖例示之互相垂直的2條線L₁及L₂，於長度40 mm中每隔1 mm即以上述條件進行ω掃描，藉此可在各線L₁、L₂上得到以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。此情況中，在線L₁上的各測量點中的ω掃描中，使ω軸與線L₁垂直，在線L₂上的各測量點中的ω掃描中，使ω軸與線L₂垂直。Furthermore, on the first main surface 21 of the wafer 20, ω scanning is performed at intervals of 1 mm along two mutually perpendicular lines_L1 and_L2 as shown in FIG. 7, respectively, within a length of 40 mm, thereby obtaining (004) XRD swing curves of 40 measurement points arranged at 1 mm intervals on each line_L1 and_L2 . In this case, in the ω scanning at each measurement point on the line_L1 , the ω axis is made perpendicular to the line_L1 , and in the ω scanning at each measurement point on the line_L2 , the ω axis is made perpendicular to the line_L2 .

較佳例之中，在第一主面21上，分別沿著至少2條互相垂直的線進行此測量時，在各線上的所有測量點之間的（004）XRD搖擺曲線FWHM的最大值會在20 arcsec以下。亦即，該2條線中，一條的40個測量點之間的最大值與另一條的40個測量點之間的最大值皆會在20 arcsec以下。各線上的所有測量點之間的（004）XRD搖擺曲線FWHM的平均值可為18 arcsec以下，進一步可為16 arcsec以下，進一步可為14 arcsec以下，進一步可為12 arcsec以下，進一步可為10 arcsec以下。In a preferred embodiment, when the measurement is performed along at least two mutually perpendicular lines on the first main surface 21, the maximum value of the FWHM of the (004) XRD swing curve between all the measurement points on each line is less than 20 arcsec. That is, the maximum value between 40 measurement points of one line and the maximum value between 40 measurement points of the other line are both less than 20 arcsec.The average value of the FWHM of the (004) XRD swing curve between all the measurement points on each line can be less than 18 arcsec, further less than 16 arcsec, further less than 14 arcsec, further less than 12 arcsec, further less than 10 arcsec.

晶圓20的第一主面21上的差排密度較佳可為2×10⁵cm^-2以下，更佳為1×10⁵cm^-2以下，再佳為5×10⁴cm^-2以下。在差排密度的評估中，可將俯視晶圓20時與外周距離小於5 mm的部分排除。2.4. 用途The dislocation density on the first main surface 21 of the wafer 20 is preferably 2×10⁵ cm^-2 or less, more preferably 1×10⁵ cm^-2 or less, and even more preferably 5×10⁴ cm^-2 or less. In the evaluation of the dislocation density, the portion that is less than 5 mm from the periphery when the wafer 20 is viewed from above may be excluded. 2.4. Application

晶圓20，可作為基板而較佳地用於製造各種氮化物半導體裝置。氮化物半導體裝置，係裝置結構的主要部分由氮化物半導體所形成的半導體裝置。氮化物半導體，亦稱為氮化物系III-V族化合物半導體、III族氮化物系化合物半導體、GaN系半導體等，除了包含GaN以外，亦包含以其他週期表第13族元素（B、Al、In等）將GaN中部分或全部的鎵取代的化合物。使用晶圓20製造所得到的氮化物半導體裝置的代表例，係發光二極體（LED）、雷射二極體（LD）等的發光裝置與整流器、雙極性電晶體、場效電晶體、高電子移動率電晶體（HEMT，High Electron Mobility Transistor）等的電子裝置，但不限於此等。Wafer 20 can be used as a substrate and is preferably used to manufacture various nitride semiconductor devices.Nitride semiconductor devices are semiconductor devices in which the main part of the device structure is formed by nitride semiconductors. Nitride semiconductors are also called nitride-based III-V compound semiconductors, III-nitride-based compound semiconductors, GaN-based semiconductors, etc. In addition to GaN, they also include compounds in which part or all of the gallium in GaN is replaced by other elements of Group 13 of the periodic table (B, Al, In, etc.).Representative examples of nitride semiconductor devices manufactured using the wafer 20 include light emitting diodes (LEDs), laser diodes (LDs), and other light emitting devices, and electronic devices such as rectifiers, bipolar transistors, field effect transistors, and high electron mobility transistors (HEMTs), but are not limited thereto.

在製造氮化物半導體裝置時，在晶圓20的第一主面21上使一層以上的氮化物半導體層磊晶成長，形成具備半導體裝置結構的磊晶晶圓。作為磊晶成長法，較佳係例示為金屬有機氣相沈積（MOCVD）、分子束磊晶（MBE）、脈衝蒸鍍、濺鍍、HVPE等的氣相法，但不限於此等。在執行了包含蝕刻加工、離子注入、賦予電極及保護膜等結構物等的半導體製程後，磊晶晶圓在因應需求進行薄化加工後進行分割，而成為氮化物半導體裝置晶片。該薄化加工中，晶圓20的第二主面22側被研削、研磨及/或蝕刻。When manufacturing a nitride semiconductor device, one or more nitride semiconductor layers are epitaxially grown on the first main surface 21 of the wafer 20 to form an epitaxial wafer having a semiconductor device structure. As an epitaxial growth method, a gas phase method such as metal organic vapor deposition (MOCVD), molecular beam epitaxy (MBE), pulse evaporation, sputtering, HVPE, etc. is preferably exemplified, but not limited to these.After performing a semiconductor process including etching, ion implantation, and providing structures such as electrodes and protective films, the epitaxial wafer is thinned as required and then divided to become a nitride semiconductor device chip. In the thinning process, the second main surface 22 side of the wafer 20 is ground, polished and/or etched.

晶圓20僅由UID-GaN所構成時，通常不會在晶圓20的表面形成電極。一例中，使用僅由UID-GaN構成的晶圓20形成磊晶晶圓後，從該磊晶晶圓將晶圓20整個研削、研磨及/或蝕刻，藉此可將其去除。晶圓20，如第五圖所示，在第一主面21側具有以ID-GaN形成之第一區域R₁、第二主面22側具有以UID-GaN形成之第二區域R₂時，於一例中，使用晶圓20形成磊晶晶圓後，藉由從晶圓20研削、研磨及/或蝕刻第二區域R₂而將其去除，而能夠在因此露出的第一區域R₁的表面上形成電極。晶圓20僅由ID-GaN所構成時，於一例中，使用晶圓20形成磊晶晶圓後，可在晶圓20的第二主面22上形成電極。該電極的形成，可在磊晶晶圓的薄化步驟之後進行。When the wafer 20 is composed only of UID-GaN, electrodes are usually not formed on the surface of the wafer 20. In one example, after forming an epitaxial wafer using the wafer 20 composed only of UID-GaN, the wafer 20 can be removed by grinding, polishing and/or etching the entire wafer 20 from the epitaxial wafer. When the wafer 20, as shown in FIG. 5, has a first region R₁ formed of ID-GaN on the first main surface 21 side and a second region R₂ formed of UID-GaN on the second main surface 22 side, in one example, after forming an epitaxial wafer using the wafer 20, the second region R 2 is removed by grinding, polishing and/or etching the second region R₂ from the wafer 20, and an electrode can be formed on the surface of the first region R₁ thus exposed. When the wafer 20 is composed of only ID-GaN, in one example, after the wafer 20 is used to form an epitaxial wafer, an electrode can be formed on the second main surface 22 of the wafer 20. The formation of the electrode can be performed after the epitaxial wafer is thinned.

晶圓20，亦可作為構成雙層GaN晶圓之一部分的材料使用。第八圖所示的雙層晶圓40，係雙層GaN晶圓的一例，其具有由晶圓20的至少一部所構成的底層L_b與在晶圓20的Ga極性側的主面上磊晶成長的GaN所構成的表層L_f。表層L_f與底層L_b之間存在再成長界面43。The wafer 20 can also be used as a material constituting a part of a double-layer GaN wafer. The double-layer wafer 40 shown in FIG. 8 is an example of a double-layer GaN wafer, which has a bottom layer L_b formed by at least a part of the wafer 20 and a surface layer L_f formed by epitaxially grown GaN on the main surface of the Ga polar side of the wafer 20. A re-growth interface 43 exists between the surface layer L_f and the bottom layer L_b .

雙層晶圓40，與晶圓20相同地，在氮化物半導體裝置的製造中，係預期作為基板使用。因此，其厚度與一般的GaN晶圓相同，直徑為約2英吋時，較佳為250~500μm，更佳為300~450μm，直徑為約4英吋時，較佳為400~800μm，更佳為500~650μm，直徑為約6英吋時，較佳為500~850μm，更佳為600~750μm。The double-layer wafer 40 is intended to be used as a substrate in the manufacture of nitride semiconductor devices, similar to the wafer 20. Therefore, its thickness is the same as that of a general GaN wafer, preferably 250-500 μm, more preferably 300-450 μm when the diameter is about 2 inches, preferably 400-800 μm, more preferably 500-650 μm when the diameter is about 4 inches, and preferably 500-850 μm, more preferably 600-750 μm when the diameter is about 6 inches.

表層L_f的厚度較佳為相同，但並非必要。雙層晶圓40中，再成長界面43相對於Ga極性側的主面41傾斜時，表層L_f的厚度沿著該傾斜方向變化。表層L_f的最小厚度，亦即厚度最小之處的厚度至少為20 μm，較佳可為50 μm以上、75 μm以上、100 μm以上等。雙層晶圓40的厚度超過300μm時，表層L_f的最大厚度，亦即厚度最大之處的厚度較佳為300 μm以下，更佳為250 μm以下，再佳為200 μm以下。表層L_f的最大厚度與最小厚度的差為200 μm以下，較佳為100 μm以下，更佳為50 μm以下，再佳為25 μm以下，再更佳為10 μm以下。The thickness of the surface layer_Lf is preferably the same, but it is not necessary. In the double-layer wafer 40, when the re-growth interface 43 is tilted relative to the main surface 41 on the Ga polarity side, the thickness of the surface layer_Lf changes along the tilt direction. The minimum thickness of the surface layer_Lf , that is, the thickness at the smallest thickness is at least 20 μm, preferably 50 μm or more, 75 μm or more, 100 μm or more, etc. When the thickness of the double-layer wafer 40 exceeds 300 μm, the maximum thickness of the surface layer_Lf , that is, the thickness at the largest thickness is preferably less than 300 μm, more preferably less than 250 μm, and even more preferably less than 200 μm. The difference between the maximum thickness and the minimum thickness of the surface layer_Lf is 200 μm or less, preferably 100 μm or less, more preferably 50 μm or less, further preferably 25 μm or less, and further preferably 10 μm or less.

表層L_f中，從頂面至少距離5 μm以內的部分，包含於高載子濃度區域或載子補償區域。表層L_f之頂面，換言之，係雙層晶圓40的Ga極性側的主面41。較佳例中，在表層L_f之中，從頂面距離Z以內的部分，包含於高載子濃度區域或載子補償區域。此處，只要不超過表層L_f的最小厚度，則Z可為20 μm以上且小於50 μm、50 μm以上且小於100 μm、100 μm以上且小於150 μm、150 μm以上且250 μm以下等。In the surface layer_Lf , the portion at least within 5 μm from the top surface is included in the high carrier concentration region or the carrier compensation region. The top surface of the surface layer_Lf , in other words, is the main surface 41 of the Ga polarity side of the double-layer wafer 40. In a preferred example, in the surface layer_Lf , the portion within a distance Z from the top surface is included in the high carrier concentration region or the carrier compensation region. Here, as long as it does not exceed the minimum thickness of the surface layer_Lf , Z can be greater than 20 μm and less than 50 μm, greater than 50 μm and less than 100 μm, greater than 100 μm and less than 150 μm, greater than 150 μm and less than 250 μm, etc.

高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域。高載子濃度區域，可為載子濃度下限為2×10¹⁸cm^-3以上、3×10¹⁸cm^-3以上、或4×10¹⁸cm^-3以上的區域。高載子濃度區域中添加的施體雜質，較佳為Si及Ge。高載子濃度區域可為載子濃度下限為4×10¹⁸cm^-3以上且施體雜質的總濃度下限為5×10¹⁸atoms/cm³以上、6×10¹⁸atoms/cm³以上或8×10¹⁸atoms/cm³以上的區域。高載子濃度區域中的施體雜質的總濃度，為了避免結晶品質明顯降低，可為5×10¹⁹atoms/cm³以下，進一步可為2×10¹⁹atoms/cm³以下，進一步可為1×10¹⁹atoms/cm³以下。高載子濃度區域中，載子濃度沿著c軸方向的變動，相較於中間值，較佳係在±25 %以內，更佳為±20 %以內，再佳為±15 %以內、再更佳為±10 %以內。難以測量載子濃度的情況，亦可以施體雜質的總濃度代替。The high carrier concentration region is a region where the lower limit of the carrier concentration is 1×10¹⁸ cm^-3 or more. The high carrier concentration region may be a region where the lower limit of the carrier concentration is 2×10¹⁸ cm^-3 or more, 3×10¹⁸ cm^-3 or more, or 4×10¹⁸ cm^-3 or more. The donor impurities added to the high carrier concentration region are preferably Si and Ge. The high carrier concentration region may be a region where the lower limit of the carrier concentration is 4×10¹⁸ cm^-3 or more and the lower limit of the total concentration of the donor impurities is 5×10¹⁸ atoms/cm³ or more, 6×10¹⁸ atoms/cm³ or more, or 8×10¹⁸ atoms/cm³ or more. In order to avoid a significant decrease in crystal quality, the total concentration of donor impurities in the high carrier concentration region may be less than 5×10¹⁹ atoms/cm³ , further less than 2×10¹⁹ atoms/cm³ , and further less than 1×10¹⁹ atoms/cm^3. In the high carrier concentration region, the variation of carrier concentration along the c-axis direction is preferably within ±25%, more preferably within ±20%, further preferably within ±15%, and further preferably within ±10% relative to the median value. In the case where it is difficult to measure the carrier concentration, the total concentration of donor impurities may be used instead.

載子補償區域，係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。載子補償區域，可為補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上、1×10¹⁸atoms/cm³以上、2×10¹⁸atoms/cm³以上或5×10¹⁸atoms/cm³以上的區域。補償雜質，係在GaN結晶中具有補償n型載子之功能的雜質。較佳的補償雜質為C（碳）與過渡金屬元素，作為過渡金屬元素，較佳可例示Fe（鐵）、Mn（錳）、Co（鈷）、Cr（鉻）、V（釩）、Ni（鎳）、Cu（銅）等。載子補償區域中的補償雜質的總濃度，為了避免結晶品質明顯降低，可為5×10¹⁹atoms/cm³以下，進一步可為2×10¹⁹atoms/cm³以下，進一步可為1×10¹⁹atoms/cm³以下。載子補償區域中，補償雜質的總濃度沿著c軸方向的變動，相較於中間值，較佳為±25 %以內，更佳為±20 %以內，再佳為±15 %以內，再更佳為±10 %以內。The carrier compensation region is a region where the lower limit of the total concentration of the compensating impurities is 2×10¹⁷ atoms/cm³ or more. The carrier compensation region may be a region where the lower limit of the total concentration of the compensating impurities is 5×10¹⁷ atoms/cm³ or more, 1×10¹⁸ atoms/cm³ or more, 2×10¹⁸ atoms/cm³ or more, or 5×10¹⁸ atoms/cm³ or more. The compensating impurities are impurities that have the function of compensating n-type carriers in the GaN crystal. Preferable compensating impurities are C (carbon) and transition metal elements. Preferable examples of transition metal elements include Fe (iron), Mn (manganese), Co (cobalt), Cr (chromium), V (vanadium), Ni (nickel), and Cu (copper). The total concentration of compensating impurities in the carrier compensation region may be less than 5×10¹⁹ atoms/cm³ , further less than 2×10¹⁹ atoms/cm³ , and further less than 1×10¹⁹ atoms/cm³ in order to avoid a significant decrease in crystal quality. In the carrier compensation region, the variation of the total concentration of the compensation impurities along the c-axis direction is preferably within ±25%, more preferably within ±20%, further preferably within ±15%, and further preferably within ±10%, relative to the median value.

製造雙層晶圓40時，首先準備晶圓20，接著在晶圓20的Ga極性側的主面上使GaN層磊晶成長，而得到積層體。晶圓20較佳係僅以UID-GaN構成。GaN層的成長方法並未限定，雖可為MOCVD，但較佳為HVPE。GaN層的成長厚度較佳為500 μm以下。藉由蓄意地對於GaN層的至少一部分進行摻雜，可設置高載子濃度區域或載子補償區域。可因應需求設置薄化步驟，以將由GaN層的成長所得之積層體薄化。薄化步驟中，將晶圓20的N極性側與GaN層的Ga極性側任一者或兩者研削、研磨及/或蝕刻。When manufacturing the double-layer wafer 40, the wafer 20 is first prepared, and then the GaN layer is epitaxially grown on the main surface of the Ga polar side of the wafer 20 to obtain a laminate. The wafer 20 is preferably composed of UID-GaN only.The growth method of the GaN layer is not limited, and although it can be MOCVD, HVPE is preferably used. The growth thickness of the GaN layer is preferably less than 500 μm. By intentionally doping at least a portion of the GaN layer, a high carrier concentration region or a carrier compensation region can be set.A thinning step can be set as needed to thin the laminate obtained by growing the GaN layer. In the thinning step, either or both of the N-polar side of the wafer 20 and the Ga-polar side of the GaN layer are ground, polished and/or etched.

雙層晶圓40中，可僅在表層L_f具有蓄意摻雜的高載子濃度區域或載子補償區域，其作為用以製造氮化物半導體裝置之基板的功能，並不比整體蓄意摻雜的GaN晶圓差。這是因為一般在氮化物半導體裝置的製造過程中包含磊晶晶圓的薄化步驟，而作為基板使用的GaN晶圓在此步驟中從背面側被加工，其中絕大部分被去除。雙層晶圓40中，為了在氮化物半導體裝置的製造過程中底層L_b即使完全被去除，而剩餘的表層L_f仍可作為支撐氮化物半導體裝置晶片之結構的基板而發揮功能，該表層L_f的最小厚度至少為20 μm，較佳為50 μm以上。In the double-layer wafer 40, only the surface layer_Lf may have a high carrier concentration region or a carrier compensation region that is intentionally doped, and its function as a substrate for manufacturing nitride semiconductor devices is no worse than that of a GaN wafer that is intentionally doped as a whole. This is because the manufacturing process of nitride semiconductor devices generally includes a step of thinning the epitaxial wafer, and the GaN wafer used as the substrate is processed from the back side in this step, and most of it is removed. In the double-layer wafer 40, in order to ensure that the remaining surface layer_Lf can still function as a substrate supporting the structure of the nitride semiconductor device chip even if the bottom layer_Lb is completely removed during the manufacturing process of the nitride semiconductor device, the minimum thickness of the surface layer_Lf is at least 20 μm, preferably above 50 μm.

除了上述以外，晶圓20，亦可在使用HVPE、THVPE（Tri-Halide Vapor Phase Epitaxy，三鹵化物汽相磊晶）、OVPE（Oxide Vapor Phase Epitaxy，氧化物汽相磊晶）、氨熱法，Na助熔劑法、其他各種的方法使塊體GaN結晶成長時，作為晶種晶圓使用。晶圓20中僅以UID-GaN形成者特別適合該用途。3. GaN結晶的成長方法In addition to the above, wafer 20 can also be used as a seed wafer when growing bulk GaN crystals using HVPE, THVPE (Tri-Halide Vapor Phase Epitaxy), OVPE (Oxide Vapor Phase Epitaxy), ammonothermal method, Na flux method, and other various methods. Wafer 20 formed only by UID-GaN is particularly suitable for this purpose.3. Growth method of GaN crystal

以下說明實施態樣之n型GaN結晶或GaN晶圓的製造中，或是實施態樣之GaN晶圓的製造方法中可較佳使用的GaN結晶的成長方法。3.1. HVPE裝置實施態樣之n型GaN結晶或GaN晶圓的製造中、或實施態樣之GaN晶圓的製造方法中可使用之HVPE裝置的基本構成顯示於第九圖。若參照第九圖，HVPE裝置100具備：熱壁型的反應器101、配置於該反應器內的鎵儲存槽102及載台103、配置於該反應器外部的第一加熱器104及第二加熱器105。第一加熱器104及第二加熱器105，分別環狀地圍住反應器101。The following describes a method for growing GaN crystals that can be preferably used in the manufacture of n-type GaN crystals or GaN wafers of the embodiment, or in the method for manufacturing GaN wafers of the embodiment.3.1. HVPE deviceThe basic structure of the HVPE device that can be used in the manufacture of n-type GaN crystals or GaN wafers of the embodiment, or in the method for manufacturing GaN wafers of the embodiment is shown in FIG. 9.Referring to FIG. 9, the HVPE device 100 includes: a hot wall type reactor 101, a gallium storage tank 102 and a carrier 103 disposed in the reactor, and a first heater 104 and a second heater 105 disposed outside the reactor. The first heater 104 and the second heater 105 respectively surround the reactor 101 in a ring shape.

反應器101為石英管腔體。反應器101內，具有主要以第一加熱器104加熱的第一區域Z₁、主要以第二加熱器105加熱的第二區域Z₂。排氣管P_E連接於第二區域Z₂側的反應器端。配置於第一區域Z₁的鎵儲存槽102，係具有氣體入口與氣體出口的石英容器。配置於第二區域Z₂的載台103，例如係以石墨形成。可隨意設置使載台103旋轉的機構。The reactor 101 is a quartz tube cavity. The reactor 101 has a first zone_Z1 mainly heated by a first heater 104 and a second zone_Z2 mainly heated by a second heater 105. The exhaust pipe_PE is connected to the reactor end on the side of the second zone_Z2 . The gallium storage tank 102 arranged in the first zone_Z1 is a quartz container having a gas inlet and a gas outlet. The carrier 103 arranged in the second zone_Z2 is formed of graphite, for example. A mechanism for rotating the carrier 103 can be arbitrarily provided.

載台103上配置有晶種。較佳係如第十（a）圖所示，在載台上與晶種一起配置將晶種邊緣圍住的邊緣遮罩。邊緣遮罩例如係以石墨形成，其高度h，如第十（b）圖所示，係以在晶種上成長的GaN厚膜之頂面的位置，在其成長結束時不會高於邊緣遮罩之上端的方式設定。邊緣遮罩，如第十一圖所示，除了晶種的邊緣以外，亦可覆蓋晶種之主面的外周部。A seed crystal is arranged on the carrier 103. Preferably, as shown in FIG. 10 (a), an edge mask that surrounds the edge of the seed crystal is arranged on the carrier together with the seed crystal. The edge mask is formed of graphite, for example, and its height h is set in such a way that the top surface of the GaN thick film grown on the seed crystal will not be higher than the upper end of the edge mask when its growth is completed, as shown in FIG. 10 (b). The edge mask, as shown in FIG. 11, can cover the outer periphery of the main surface of the seed crystal in addition to the edge of the seed crystal.

在大面積晶種上使GaN結晶厚膜成長時，邊緣遮罩發揮重要的功能。本案發明人等的經驗中，在使用直徑2英吋的圓形GaN晶圓作為晶種時，為了避免晶圓所切出之厚度的GaN層破裂而使其成長，必須使用邊緣遮罩。另一方面，在將面積大於直徑2英吋的圓但具有矩形主面的GaN晶圓作為晶種時，即使無邊緣遮罩，亦可在避免晶圓所切出之厚度的GaN膜破裂的情況下使其成長。然而，在無邊緣遮罩的情況下成長的GaN厚膜其表面形態不佳，沿著外緣形成在c軸方向上突出的隆起，而在該隆起的內側壁面密集產生大型的凹槽，此外在該隆起的表面亦觀察到微細的裂縫。若沿著c面將該GaN厚膜切開，則會產生從邊緣往中央部延伸的裂縫，而無法取得預期的晶圓。When growing a thick GaN crystal film on a large-area seed, an edge mask plays an important role.In the experience of the inventors of this case, when a 2-inch diameter round GaN wafer is used as a seed, an edge mask must be used to prevent the GaN layer of the thickness cut from the wafer from being broken and growing.On the other hand, when a GaN wafer with an area larger than a 2-inch diameter round but with a rectangular main surface is used as a seed, it can be grown without breaking the GaN film of the thickness cut from the wafer even without an edge mask. However, the surface morphology of the GaN thick film grown without edge mask is not good. A ridge protruding in the c-axis direction is formed along the outer edge, and large grooves are densely generated on the inner wall of the ridge. In addition, fine cracks are observed on the surface of the ridge. If the GaN thick film is cut along the c-plane, cracks extending from the edge to the center will be generated, and the expected wafer cannot be obtained.

再次回到第九圖，在使GaN結晶成長時，以第一加熱器104及第二加熱器105將反應器101內加熱的同時，將以載子氣體稀釋的NH₃（氨）通過氨導入管P₁而供給至第二區域Z₂，又，將以載子氣體稀釋的HCl（氯化氫）通過氯化氫導入管P₂而供給至鎵儲存槽102。該HCl與鎵儲存槽102之中的金屬鎵反應，產生的GaCl（氯化鎵）通過氯化鎵導入管P₃被送往第二區域Z₂。在第二區域Z₂中，NH₃與GaCl反應，產生的GaN在放置於載台103上的晶種上進行結晶化。Returning to FIG. 9, when GaN is crystallized and grown, NH₃ (ammonia) diluted with a carrier gas is supplied to the second zone Z₂ through the ammonia inlet pipe P₁ while the first heater 104 and the second heater 105 heat the reactor 101. In addition, HCl (hydrogen chloride) diluted with a carrier gas is supplied to the gallium storage tank 102 through the hydrogen chloride inlet pipe P_2. The HCl reacts with the metallic gallium in the gallium storage tank 102, and the generated GaCl (gallium chloride) is sent to the second zone Z₂ through the gallium chloride inlet pipe P_3. In the second zone Z₂ , NH₃ reacts with GaCl, and the generated GaN is crystallized on the seed placed on the carrier 103.

以雜質對於在晶種上成長的GaN結晶進行摻雜時，將以載子氣體稀釋的摻雜氣體通過摻雜物導入管P₄導入反應器101內的第二區域Z₂。氨導入管P₁、氯化氫導入管P₂、氯化鎵導入管P₃及摻雜物導入管P₄，配置於反應器101內的部分可由石英形成。When doping the GaN crystal grown on the seed crystal with impurities, the doping gas diluted with the carrier gas is introduced into the second zone_Z2 in the reactor 101 through the doping introduction pipe_P4 . The ammonia introduction pipe_P1 , the hydrogen chloride introduction pipe_P2 , the gallium chloride introduction pipe_P3 and the doping introduction pipe_P4 , the part disposed in the reactor 101 can be formed of quartz.

第九圖中，就氨導入管P₁與氯化鎵導入管P₃而言，從噴嘴至載台103的距離相同，但並未限定，亦可在比氯化鎵導入管P₃的噴嘴更遠離載台103的位置（上游側），使氨導入管P₁的噴嘴開口。或是可使第九圖中獨立的氨導入管P₁的噴嘴與氯化鎵導入管P₃的噴嘴一體化，亦可為前者為外管、後者為內管的雙重管噴嘴。In FIG. 9, the distance from the nozzle to the carrier 103 is the same for the ammonia introduction pipe_P1 and the gallium chloride introduction pipe_P3 , but this is not limited to the above. The nozzle of the ammonia introduction pipe_P1 may be opened at a position farther from the carrier 103 (upstream side) than the nozzle of the gallium chloride introduction pipe_P3 . Alternatively, the nozzle of the independent ammonia introduction pipe_P1 and the nozzle of the gallium chloride introduction pipe_P3 in FIG. 9 may be integrated, or a double-tube nozzle may be used in which the former is an outer tube and the latter is an inner tube.

第九圖中，雖分開描繪氯化鎵導入管P₃與摻雜物導入管P₄的噴嘴，但並無限定。例如，為了對於欲進行成長的GaN結晶均勻地進行摻雜，亦可使摻雜物導入管P₄的噴嘴在氯化鎵導入管P₃內開口，以在將GaCl與摻雜氣體混合後再通過共通的噴嘴釋出至第二區域Z₂內。In FIG. 9, although the nozzles of the gallium chloride introduction tube_P3 and the dopant introduction tube_P4 are depicted separately, this is not limiting. For example, in order to uniformly dope the GaN crystals to be grown, the nozzle of the dopant introduction tube_P4 may be opened in the gallium chloride introduction tube_P3 , so that GaCl and the dopant gas are mixed and then released into the second zone_Z2 through a common nozzle.

在對於欲進行成長的GaN結晶摻雜Si時，摻雜氣體較佳係使用SiH₄（矽烷）、SiH₃Cl（單氯矽烷）、SiH₂Cl₂（二氯矽烷）、SiHCl₃（三氯矽烷）或SiCl₄（四氯矽烷）。在對於欲進行成長的GaN結晶摻雜Ge時，摻雜氣體較佳可使用GeH₄（鍺烷）、GeH₃Cl（一氯鍺烷）、GeH₂Cl₂（二氯鍺烷）、GeHCl₃（三氯鍺烷）或GeCl₄（四氯化鍺）。欲進行成長的GaN結晶，儘管非蓄意地摻雜，仍會含有O及Si。非蓄意摻雜的Si應該是源自構成反應器或配管的石英，而非蓄意摻雜的O則應該是來自該石英與從外部侵入反應器內之水分的任一者或兩者。When the GaN crystal to be grown is doped with Si, the doping gas is preferably SiH₄ (silane), SiH₃ Cl (monochlorosilane), SiH₂ Cl₂ (dichlorosilane), SiHCl₃ (trichlorosilane) or SiCl₄ (tetrachlorosilane). When the GaN crystal to be grown is doped with Ge, the doping gas is preferably GeH₄ (germanium), GeH₃ Cl (monochlorogermanium), GeH₂ Cl₂ (dichlorogermanium), GeHCl₃ (trichlorogermanium) or GeCl₄ (germanium tetrachloride). The GaN crystal to be grown, although not intentionally doped, still contains O and Si. Unintentionally doped Si is likely to originate from the quartz constituting the reactor or the piping, while unintentionally doped O is likely to originate from either or both of the quartz and moisture that has intruded into the reactor from the outside.

包含第九圖中省略的零件，配置於反應器101內的零件，除了石英與碳以外，可使用以SiC（碳化矽）、SiN_x（氮化矽）、BN（氮化硼）、氧化鋁、W（鎢）、Mo（鉬）等形成的零件。如此，在晶種上成長的GaN結晶中，除了Si、O及H以外，各雜質的濃度，只要不蓄意摻雜，皆可在5×10¹⁵atoms/cm³以下。3.2. 晶種Including the parts omitted in FIG. 9, the parts arranged in the reactor 101 may be made of SiC (silicon carbide), SiN_x (silicon nitride), BN (boron nitride), aluminum oxide, W (tungsten), Mo (molybdenum), etc., in addition to quartz and carbon. In this way, the concentration of each impurity except Si, O and H in the GaN crystal grown on the seed crystal can be less than 5×10¹⁵ atoms/cm³ as long as it is not intentionally doped. 3.2. Seed Crystal

實施態樣之n型GaN結晶或GaN晶圓的成長中所使用之晶種的較佳例，係使用NH₄F與NH₄I作為礦化劑而以酸性氨熱法成長的c面GaN晶圓，關於其製造方法，可參照前述的專利文獻1（WO2018/030311A1）。儘管該c面GaN晶圓偶爾會具有10¹⁸atoms/cm³等級中段以上的氧濃度，仍可在幾乎不發生應變的情況下以HVPE在其Ga極性側的主面上使氧濃度為3×10¹⁶atoms/cm³以下的GaN結晶成長。（0001）結晶面相對於該主面的傾斜，較佳係在0度至1度，更佳為0度至0.5度的範圍內。3.3. 成長條件A preferred example of a seed used in the growth of an n-type GaN crystal or GaN wafer of an embodiment is a c-plane GaN wafer grown by an acidic ammonothermal method using NH₄ F and NH₄ I as mineralizing agents. For its manufacturing method, reference may be made to the aforementioned patent document 1 (WO2018/030311A1). Although the c-plane GaN wafer occasionally has an oxygen concentration above the mid-range of 10¹⁸ atoms/cm³ , GaN crystals with an oxygen concentration of less than 3×10¹⁶ atoms/cm³ can be grown on the main surface of its Ga polar side by HVPE with almost no strain. The inclination of the (0001) crystal plane relative to the main surface is preferably in the range of 0 to 1 degree, more preferably in the range of 0 to 0.5 degree. 3.3. Growth Conditions

在晶種上以HVPE使GaN結晶成長時的較佳條件如下。鎵儲存槽的溫度為例如500~1000 ℃，較佳為700 ℃以上，又較佳為900 ℃以下。載台溫度為例如900~1100 ℃，較佳為930 ℃以上，更佳為950 ℃以上，又較佳為1050 ℃以下，更佳為1020 ℃以下。The preferred conditions for growing GaN crystals on a seed by HVPE are as follows.The temperature of the gallium storage tank is, for example, 500 to 1000°C, preferably 700°C or higher, and more preferably 900°C or lower.The stage temperature is, for example, 900 to 1100°C, preferably 930°C or higher, more preferably 950°C or higher, more preferably 1050°C or lower, and more preferably 1020°C or lower.

反應器內的NH₃分壓與GaCl分壓的比，即V/III比，可為例如1~20，但較佳為2以上，更佳為3以上，又較佳為10以下。V/III比太大或太小皆會成為欲進行成長之GaN的表面形態惡化的原因。表面形態的惡化，會成為結晶品質降低及不經意混入GaN結晶的氧濃度變高的原因。The ratio of the NH3_partial pressure to the GaCl partial pressure in the reactor, i.e., the V/III ratio, can be, for example, 1 to 20, but is preferably 2 or more, more preferably 3 or more, and still more preferably 10 or less. A V/III ratio that is too large or too small will cause the surface morphology of the GaN to be grown to deteriorate. The deterioration of the surface morphology will cause the quality of the crystal to decrease and the concentration of oxygen inadvertently mixed into the GaN crystal to increase.

根據雜質，混入GaN結晶的效率有時與在成長中的GaN表面露出的刻面（facet）的方位密切相依。成長中的表面形態不佳的GaN結晶的內部中，該雜質濃度的均勻性低，這是因為在表面形態不佳的表面存在各種方位的刻面所導致。這種雜質的典型例子為O（氧），但本案發明人等發現Ge（鍺）亦具有相同的傾向。如後所述，蓄意地摻雜Ge使GaN結晶成長時，較佳係不要過度降低載子氣體中的H₂之莫耳比，這也與此有關。Depending on the impurity, the efficiency of mixing into the GaN crystal is sometimes closely dependent on the orientation of the facets exposed on the growing GaN surface. The uniformity of the impurity concentration is low inside the growing GaN crystal with poor surface morphology, which is caused by the presence of facets of various orientations on the surface with poor surface morphology. A typical example of such an impurity is O (oxygen), but the inventors of this case have found that Ge (germanium) also has the same tendency. As described later, when intentionally doping Ge to grow GaN crystals, it is better not to excessively reduce the molar ratio of_H2 in the carrier gas, which is also related to this.

其他，若使用太低的V/III比，則會導致欲進行成長的GaN結晶的氮空孔濃度增加。氮空孔對於GaN晶圓或GaN晶圓上形成之氮化物半導體裝置的影響目前雖未明，但因為其為點缺陷，而認為應該盡量降低其濃度。In addition, if the V/III ratio is too low, the concentration of nitrogen vacancies in the GaN crystal to be grown will increase. The effect of nitrogen vacancies on GaN wafers or nitride semiconductor devices formed on GaN wafers is not yet clear, but since nitrogen vacancies are point defects, their concentration should be minimized.

GaN結晶的成長速率，可以反應器內的NH₃分壓與GaCl分壓的乘積作為參數而進行控制。該速率為例如20~200 μm/h，較佳為30 μm/h以上，更佳為40 μm/h以上，又，較佳為120 μm/h以下，更佳為100 μm/h以下，再佳為80 μm/h以下。本案發明人等發現，在以酸性氨熱法成長的GaN結晶所構成的高結晶品質之晶種上，以HVPE使GaN結晶成長時，若成長速率太低，則會發生在成長表面形成局部停止成長的區域這樣的問題。The growth rate of GaN crystals can be controlled by taking the product of the partial pressure of NH₃ and the partial pressure of GaCl in the reactor as a parameter. The rate is, for example, 20 to 200 μm/h, preferably 30 μm/h or more, more preferably 40 μm/h or more, and preferably 120 μm/h or less, more preferably 100 μm/h or less, and even more preferably 80 μm/h or less. The inventors of the present case have found that when GaN crystals are grown by HVPE on a seed crystal of high crystalline quality composed of GaN crystals grown by the acidic ammonothermal method, if the growth rate is too low, a problem occurs in which a region where growth stops locally is formed on the growth surface.

採用20 μm/h~50 μm/h這種低成長速率時，可較佳地防止在以酸性氨熱法成長的GaN結晶所構成的晶種、與在該晶種上以HVPE成長的GaN結晶的界面產生新的線差排。為了提升生產效率，亦可在成長的途中提升成長速率。根據本案發明人等所進行的實驗，暗示了在使最初的成長速率為40 μm/h，並在途中使成長速率上升至80 μm/h或120 μm/h時，以80 μm/h成長的GaN結晶的線差排密度，與以酸性氨熱法成長之GaN結晶所構成的晶種並無不同，而在以120 μm/h成長的GaN結晶中，線差排密度為該晶種的約2倍。提升成長速率時，應在欲進行成長的GaN結晶的表面形態不會變差的範圍內進行。針對表面形態變差所產生的問題如前所述。When a low growth rate of 20 μm/h~50 μm/h is used, it is better to prevent the generation of new line dislocations at the interface between the seed composed of GaN crystals grown by the acidic ammonothermal method and the GaN crystals grown on the seed by HVPE.In order to improve production efficiency, the growth rate can also be increased during growth. According to the experiments conducted by the inventors of this case, it is suggested that when the initial growth rate is 40 μm/h and the growth rate is increased to 80 μm/h or 120 μm/h during the growth, the line dislocation density of the GaN crystal grown at 80 μm/h is no different from that of the seed composed of GaN crystals grown by the acidic ammonothermal method, and in the GaN crystals grown at 120 μm/h, the line dislocation density is about twice that of the seed.When increasing the growth rate, it should be done within a range where the surface morphology of the GaN crystal to be grown does not deteriorate. The problems caused by deterioration of the surface morphology are as described above.

分別將NH₃、HCl及摻雜氣體稀釋的載子氣體中，可較佳地使用H₂（氫氣）、N₂（氮氣）或H₂與N₂的混合氣體。載子氣體中的H₂之莫耳比，會影響欲進行成長之GaN結晶的雜質濃度。另外，此處所指的載子氣體中的H₂之莫耳比，係根據從反應器外供給至反應器內以作為載子氣體的各種氣體之流量而算出。In the carrier gas for diluting NH₃ , HCl and the doping gas, H₂ (hydrogen), N₂ (nitrogen) or a mixed gas of H₂ and N₂ can be preferably used. The molar ratio of H₂ in the carrier gas affects the impurity concentration of the GaN crystal to be grown. In addition, the molar ratio of H₂ in the carrier gas referred to here is calculated based on the flow rate of various gases supplied from the outside of the reactor into the reactor as carrier gas.

作為參考，調查在從在藍寶石基板上以HVPE成長的GaN結晶切出的c面GaN晶圓的Ga極性面上，使用相同V/III比，以約略相同的成長速率，藉由HVPE成長的摻雜Si之GaN與摻雜Ge之GaN的雜質濃度，因為載子氣體中的H₂之莫耳比而會有多少變化，結果顯示於下述表1。使用的摻雜氣體，在Si摻雜之中為SiH₂Cl₂，在Ge摻雜中為GeCl₄。For reference, the Ga polar surface of a c-plane GaN wafer cut from a GaN crystal grown on a sapphire substrate by HVPE was investigated to see how much the impurity concentration of Si-doped GaN and Ge-doped GaN grown by HVPE at approximately the same growth rate using the same V/III ratio varies due to the molar ratio of H₂ in the carrier gas. The results are shown in Table 1 below. The doping gas used was SiH₂ Cl₂ for Si doping and GeCl₄ for Ge doping.

[表1][Table 1]

從表1可得知，摻雜Si之GaN結晶的O濃度，在載子氣體之H₂之莫耳比為0（零）時，可為Si濃度的10 %以下。Si以外的施體雜質實質上只有O，因此這相當於Si以外之施體雜質的總濃度為Si濃度的10 %以下。若提升載子氣體中的H₂之莫耳比，摻雜Si之GaN的O濃度變得更低，該莫耳比為0.7時，則會小於Si濃度的1 %。From Table 1, it can be seen that the O concentration of the Si-doped GaN crystal can be less than 10% of the Si concentration when the molar ratio of_H2 in the carrier gas is 0 (zero). The donor impurities other than Si are essentially only O, so this is equivalent to the total concentration of donor impurities other than Si being less than 10% of the Si concentration. If the molar ratio of_H2 in the carrier gas is increased, the O concentration of the Si-doped GaN becomes even lower, and when the molar ratio is 0.7, it will be less than 1% of the Si concentration.

另一方面，摻雜Ge的GaN結晶中，載子氣體中的H₂之莫耳比為0（零）時，相較於該莫耳比為0.7時，Ge濃度高出10倍以上，又，Ge濃度相對於Si濃度的比亦高。因此，乍看之下載子氣體中的H₂之莫耳比低者較佳，但未必是如此。載子氣體中的H₂之莫耳比為0（零）時，相較於該莫耳比為0.7時，O濃度亦高出1個位數，本案發明人等由此點確認在該莫耳比為0時，亦成為成長中的GaN之表面形態差、Ge濃度高的原因。因為O與Ge皆為施體雜質，因此在以載子氣體中的H₂之莫耳比太低的條件成長的GaN結晶中，會發生載子濃度的均勻性降低這樣的問題。因此，摻雜Ge時載子氣體中的H₂之莫耳比較佳為0.3~0.7左右。在此條件下成長的摻雜Ge之GaN結晶中，Ge濃度為1×10¹⁸atoms/cm³以上時，Si濃度成為4×10¹⁷atoms/cm³以上。On the other hand, in the Ge-doped GaN crystal, when the molar ratio of_H2 in the carrier gas is 0 (zero), the Ge concentration is more than 10 times higher than when the molar ratio is 0.7, and the ratio of Ge concentration to Si concentration is also high. Therefore, at first glance, the lower the molar ratio of_H2 in the carrier gas, the better, but this is not necessarily the case. When the molar ratio of_H2 in the carrier gas is 0 (zero), the O concentration is also one digit higher than when the molar ratio is 0.7. From this point, the inventors of this case confirmed that when the molar ratio is 0, it also becomes the reason for the poor surface morphology of the growing GaN and the high Ge concentration. Since both O and Ge are donor impurities, the uniformity of carrier concentration decreases in GaN crystals grown under conditions where the molar ratio of_H2 in the carrier gas is too low. Therefore, the molar ratio of_H2 in the carrier gas is preferably around 0.3~0.7 when Ge is doped. In the Ge-doped GaN crystals grown under these conditions, when the Ge concentration is 1×¹⁰¹⁸ atoms/^cm3 or more, the Si concentration becomes 4×¹⁰¹⁷ atoms/^cm3 or more.

在摻雜Si與Ge任一者時，若提升載子氣體中的H₂之莫耳比，以HVPE成長的GaN結晶的O濃度皆具有降低的傾向，其成為2×10¹⁶atoms/cm³以下，進一步可為1×10¹⁶atoms/cm³以下。這被認為是因為成長中的GaN結晶的表面形態經改善。作為晶種使用的c面GaN晶圓的結晶品質，亦會影響成長於其上的GaN結晶的表面形態。在品質高的晶種上，可成長出O濃度更低的GaN結晶。在晶種上使GaN結晶成長時，摻雜氣體可從最初即開始供給，但較佳係在GaN層的成長厚度至少達到10 μm再開始供給。又，開始供給摻雜氣體後，較佳係花費數分鐘至數十分鐘使供給速率逐漸增加至既定值。4. 實驗結果When doping either Si or Ge, if the molar ratio of_H2 in the carrier gas is increased, the O concentration of the GaN crystal grown by HVPE tends to decrease, becoming less than 2×¹⁰¹⁶ atoms/^cm3 , and further less than 1×¹⁰¹⁶ atoms/^cm3 . This is believed to be because the surface morphology of the growing GaN crystal is improved. The crystal quality of the c-plane GaN wafer used as a seed will also affect the surface morphology of the GaN crystal grown thereon. GaN crystals with lower O concentrations can be grown on high-quality seeds. When growing GaN crystals on seeds, the doping gas can be supplied from the beginning, but it is better to start supplying when the growth thickness of the GaN layer reaches at least 10 μm. Furthermore, after the doping gas is started, it is preferred to gradually increase the supply rate to a predetermined value over a period of several minutes to several tens of minutes. 4. Experimental Results

以下記載本案發明人等所進行之實驗。實驗中，在以氨熱法進行GaN結晶的成長中，係使用基本構成如第十二圖所示的結晶成長裝置。該結晶成長裝置，具備高壓釜與設於其中的Pt-Ir合金製的腔室。腔室內部具有以Pt製的擋板彼此隔開的溶解區域及成長區域。使GaN結晶成長時，溶解區域中同時放置有原料與礦化劑（圖中未顯示），而在成長區域中，係以Pt線懸吊晶種。與真空泵、氨氣鋼瓶及氮氣鋼瓶連接的氣體線，透過閥來與高壓釜及腔室連接。在使NH₃（氨）進入腔室時，可以質量流量計確認從氨鋼瓶所供給之NH₃的量。The following describes the experiments conducted by the inventors of this case. In the experiment, in the growth of GaN crystals by the ammonothermal method, a crystal growth device with the basic structure shown in Figure 12 was used. The crystal growth device has a high-pressure autoclave and a chamber made of Pt-Ir alloy arranged therein. The interior of the chamber has a dissolution zone and a growth zone separated from each other by a baffle made of Pt. When growing GaN crystals, raw materials and mineralizing agents (not shown in the figure) are placed in the dissolution zone at the same time, and in the growth zone, the seed crystal is suspended by a Pt wire. The gas lines connected to the vacuum pump, ammonia cylinder and nitrogen cylinder are connected to the high-pressure autoclave and the chamber through valves. When NH₃ (ammonia) is introduced into the chamber, the amount of NH₃ supplied from the ammonia cylinder can be confirmed by a mass flow meter.

因應進入腔室的NH₃的量，決定將腔室加熱至既定溫度時腔室內的壓力。為了平衡腔室內側與外側的壓力，不僅在腔室內，亦在高壓釜與腔室之間的空間中封入NH₃。設置晶種、原料及礦化劑，並且在NH₃的導入完成後，將腔室密封，以使內部成為超臨界狀態的方式，從高壓釜的外側以加熱器（圖中未顯示）加熱。為了在溶解區域與成長區域之間設置溫度梯度，而以複數的加熱器分別將高壓釜的上部與下部加熱。4.1. 實驗1（1）晶種的準備The pressure inside the chamber when the chamber is heated to a predetermined temperature is determined by the amount of NH₃ entering the chamber. In order to balance the pressure inside and outside the chamber, NH₃ is sealed not only inside the chamber but also in the space between the autoclave and the chamber. Seed crystals, raw materials, and mineralizing agents are placed, and after the introduction of NH₃ is completed, the chamber is sealed so that the interior becomes a supercritical state, and then heated from the outside of the autoclave with a heater (not shown in the figure). In order to set a temperature gradient between the dissolution zone and the growth zone, the upper and lower parts of the autoclave are heated separately with multiple heaters. 4.1. Experiment 1 (1) Preparation of seed crystals

首先，準備使用NH₄F及NH₄I作為礦化劑的氨熱法進行成長、厚度0.4 mm的第一c面GaN晶圓。在該第一c面GaN晶圓中經過鏡面拋光的N極性面上，使用掀離（lift-off）法，形成在厚度100 nm的TiW底層上積層厚度100 nm之Pt表面層的雙層結構濺鍍膜所構成之條紋圖案的選擇成長遮罩。該選擇成長遮罩中設置的線狀開口的線寬度為50 μm，線狀開口間之間距為2 mm。條紋方向與構成該晶圓的GaN結晶之a面平行。First, prepare the first c-plane GaN wafer with a thickness of 0.4 mm, grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents. On the mirror-polished N-polar surface of the first c-plane GaN wafer, use the lift-off method to form a stripe pattern selective growth mask consisting of a double-layer structure sputter-plated film of a 100 nm thick Pt surface layer stacked on a 100 nm thick TiW bottom layer. The line width of the linear openings set in the selective growth mask is 50 μm, and the spacing between the linear openings is 2 mm. The stripe direction is parallel to the a-plane of the GaN crystal constituting the wafer.

將在N極性面上形成此選擇成長遮罩的第一c面GaN晶圓作為晶種使用，以氨熱法使GaN結晶成長。氨熱步驟中，使用多晶GaN作為原料，並且使用NH₄F及NH₄I作為礦化劑。該多晶GaN係以在加熱下使單體Ga與HCl氣體接觸而產生氣體GaCl，再使該氣體GaCl與NH₃氣體反應的方法而製造。礦化劑的加入量，針對NH₄F及NH₄I，以與NH₃溶劑相對之莫耳比計，分別為1.0 %。NH₄I礦化劑，係在作為反應容器的Pt-Ir腔室內，藉由使HI（碘化氫）氣體與NH₃反應而合成。The first c-plane GaN wafer with the selective growth mask formed on the N polar surface is used as a seed crystal to grow GaN by the ammonothermal method. In the ammonothermal step, polycrystalline GaN is used as a raw material, and NH₄ F and NH₄ I are used as mineralizing agents. The polycrystalline GaN is manufactured by a method in which a single Ga is brought into contact with HCl gas under heating to generate gaseous GaCl, and then the gaseous GaCl is reacted with NH₃ gas. The amount of mineralizing agent added is 1.0% for NH₄ F and NH₄ I, respectively, in terms of molar ratio relative to NH₃ solvent. The_{NH 4} I mineralizing agent is synthesized by reacting HI (hydrogen iodide) gas with NH₃ in a Pt-Ir chamber serving as a reaction vessel.

在氨熱步驟中，溶解區域的溫度T₁與成長區域的溫度T₂的平均值為600 ℃至620 ℃之間，兩區域間的溫度差T₁-T₂（T₁＞T₂）係從5 ℃至10 ℃之間，腔室內壓力為200 MPa至230 MPa之間。此條件維持30天以上。在第一c面GaN晶圓的N極性面上，如第十三圖所示，以使GaN結晶成為層狀的方式進行成長，其厚度t為3 mm。在與選擇成長遮罩鄰接之部分形成孔洞，該孔洞的高度h，亦即從選擇成長遮罩之頂面至孔洞上端的距離，在0.5 mm至1 mm之間。此處註記，雖GaN結晶亦在第一c面GaN晶圓的Ga極性面上成長，但第十三圖中省略圖示。In the ammonothermal step, the average values of the temperature_T1 of the dissolution zone and the temperature_T2 of the growth zone are between 600°C and 620°C, the temperature difference_T1 -_T2 (_T1 >_T2 ) between the two zones is between 5°C and 10°C, and the pressure in the chamber is between 200 MPa and 230 MPa. This condition is maintained for more than 30 days. On the N-polar surface of the first c-plane GaN wafer, as shown in FIG. 13, GaN is grown in a layered manner so that the crystal is formed, and its thickness t is 3 mm. A hole is formed in the portion adjacent to the selective growth mask, and the height h of the hole, that is, the distance from the top surface of the selective growth mask to the upper end of the hole, is between 0.5 mm and 1 mm. Note here that although GaN crystals also grow on the Ga polar plane of the first c-plane GaN wafer, they are omitted in FIG. 13 .

接著，將已成長的GaN結晶層加工，形成厚度0.4 mm的第二c面GaN晶圓。第二c面GaN晶圓的Ga極性面，在以研削進行鏡面平坦化後，為了去除損傷層而以CMP加工。若對於以與該第二c面GaN晶圓相同方法製作的c面GaN晶圓測量（004）XRD搖擺曲線的半高全寬，則得到小於10 arcsec的值。（2）摻雜Ge之c面GaN晶圓的製作Next, the grown GaN crystal layer is processed to form a second c-plane GaN wafer with a thickness of 0.4 mm. The Ga polar surface of the second c-plane GaN wafer is mirror-planarized by grinding and then processed by CMP to remove the damaged layer. If the half-height full width of the (004) XRD swing curve is measured for a c-plane GaN wafer made in the same way as the second c-plane GaN wafer, a value of less than 10 arcsec is obtained. (2) Preparation of Ge-doped c-plane GaN wafer

使用將上述第二c面GaN晶圓分割而成的、Ga極性面的面積約7 cm²且厚度為0.4 mm的c面GaN晶圓作為晶種，在其Ga極性面上，使用具備與第九圖所示之HVPE裝置共通之基本構成的氣相成長裝置，以HVPE使GaN厚膜成長。其程序大致記載如下。首先，在載台上設置晶種。不使用邊緣遮罩。接著，一邊以使N₂、H₂及NH₃的分壓分別為0.25 atm、0.73 atm及0.02 atm的方式將其供給至反應器內，一邊藉由設於反應器外側的加熱器將反應器加熱。A c-plane GaN wafer obtained by dividing the above-mentioned second c-plane GaN wafer, with a Ga polar surface area of about 7^cm2 and a thickness of 0.4 mm, is used as a seed crystal. On its Ga polar surface, a vapor phase growth device having a basic structure common to the HVPE device shown in Figure 9 is used to grow a GaN thick film by HVPE. The procedure is roughly described as follows. First, a seed crystal is set on a carrier. No edge mask is used. Then, while_N2 ,_H2 and_NH3 are supplied into the reactor in such a way that the partial pressures are 0.25 atm, 0.73 atm and 0.02 atm respectively, the reactor is heated by a heater arranged outside the reactor.

載台溫度到達1002 ℃後，將載台溫度保持定值，使GaN成長。Ga儲存槽的溫度設為800 ℃。供給至反應器內的載子氣體，以莫耳比計，使H₂為69 %，而剩餘部分為N₂。在成長開始之後的60分鐘內，以使GaCl及NH₃的分壓分別為7.7×10^-3atm及2.3×10^-2atm的方式將其供給至反應器內，並且不蓄意供給摻雜氣體。After the stage temperature reached 1002°C, the stage temperature was kept constant to allow GaN to grow. The temperature of the Ga storage tank was set to 800°C. The carrier gas supplied to the reactor was 69% H₂ and the remainder N₂ in terms of molar ratio. Within 60 minutes after the start of growth, GaCl and NH₃ were supplied to the reactor in such a way that the partial pressures were 7.7×10^-3 atm and 2.3×10^-2 atm, respectively, and no doping gas was intentionally supplied.

成長開始60分鐘後，開始對反應器內供給GeCl₄（四氯化鍺）。花費5分鐘逐漸增加GeCl₄的供給速率。GeCl₄的供給速率到達既定值後，以使GaCl、NH₃及GeCl₄的分壓分別為7.7×10^-3atm、2.3×10^-2atm及1.7×10^-7atm的方式將其供給至反應器內，使摻雜Ge的GaN厚膜成長約2.7 mm。從厚度與成長時間算出的摻雜Ge之GaN厚膜的成長速率約為33 μm/min。60 minutes after the start of growth, GeCl₄ (germanium tetrachloride) was fed into the reactor. The feeding rate of GeCl₄ was gradually increased over 5 minutes. After the feeding rate of GeCl₄ reached the set value, GaCl, NH₃ and GeCl 4 were fed into the reactor in such a way that the partial pressures of GaCl, NH 3 and GeCl₄ were 7.7×10^-3 atm, 2.3×10^-2 atm and 1.7×10^-7 atm, respectively, so that the Ge-doped GaN thick film grew to about 2.7 mm. The growth rate of the Ge-doped GaN thick film calculated from the thickness and growth time was about 33 μm/min.

接著，與c面平行地切開該摻雜Ge之GaN厚膜，對於所得之晶圓的Ga極性面，實施以研削所進行的平坦化，之後進行CMP加工。以蝕刻去除該晶圓的N極性面側的切割損傷。再者，藉由裁切晶圓，完成厚度335 μm、主面的面積約7 cm²的摻雜Ge之c面GaN晶圓（以下亦稱為「樣本E-1」）。（3）評估＜（004）XRD搖擺曲線FWHM＞Next, the Ge-doped GaN thick film was cut parallel to the c-plane, and the Ga-polar surface of the resulting wafer was flattened by grinding, followed by CMP processing. Cutting damage on the N-polar surface side of the wafer was removed by etching. Furthermore, by cutting the wafer, a Ge-doped c-plane GaN wafer with a thickness of 335 μm and a main surface area of approximately 7^cm2 was completed (hereinafter also referred to as "sample E-1"). (3) Evaluation <(004) XRD wobble curve FWHM>

在Ga極性面上從邊緣離開的位置上，進行樣本E-1的（004）XRD搖擺曲線測量。在測量中，以45 kV、40 mA使X射線繞射裝置［Spectris (股)製 PANalytical X’Pert Pro MRD］所具備的線聚焦CuKα射線源運作，使用Ge（440）4結晶對稱單色儀，得到CuKα₁線。使用之光學系統為平行光學系統，在入射側使用1/2狹縫、X射線鏡及w1mm×h1mm的十字狹縫。檢測器係使用半導體像素檢測器PIXcel^3D（註冊商標）的0D模式。角解析度（Angular resolution）為5~6 arcsec。The (004) XRD swing curve of sample E-1 was measured at a position away from the edge on the Ga polar surface. During the measurement, the line-focused CuKα radiation source of the X-ray diffraction device [PANalytical X'Pert Pro MRD manufactured by Spectris (Co., Ltd.)] was operated at 45 kV and 40 mA, and the CuKα₁ line was obtained using a Ge (440) 4 crystal symmetric monochromator. The optical system used was a parallel optical system, with a 1/2 slit, an X-ray mirror, and a cross slit of w1mm×h1mm on the incident side. The detector used was the 0D mode of the semiconductor pixel detector PIXcel^3D (registered trademark). The angular resolution was 5~6 arcsec.

X射線的光束尺寸，在使入射角為90°時，亦即使X射線垂直入射試片基板的Ga極性面時，該Ga極性面上的照射區域的尺寸，係針對與ω軸平行的方向設定為5 mm，針對與ω軸垂直的方向設定為1 mm。搖擺曲線測量中，從與GaN結晶的a軸垂直的方向將X射線射入試片。換言之，使X射線的入射面與GaN結晶的a面平行。（004）XRD搖擺曲線的FWHM為8.5 arcsec。＜電特性＞The beam size of the X-rays, when the incident angle is 90°, that is, when the X-rays are perpendicular to the Ga polar surface of the sample substrate, the size of the irradiation area on the Ga polar surface is set to 5 mm in the direction parallel to the ω axis and 1 mm in the direction perpendicular to the ω axis.In the wobble curve measurement, the X-rays are projected into the sample from the direction perpendicular to the a-axis of the GaN crystal. In other words, the incident plane of the X-rays is parallel to the a-plane of the GaN crystal. The FWHM of the (004) XRD wobble curve is 8.5 arcsec.<Electrical characteristics>

樣本E-1的室溫電阻率與由霍爾測量所求得之室溫的載子濃度及載子移動度，分別為0.012 Ω･cm、1.5×10¹⁸cm^-3及347 cm²/V･s。＜雜質濃度＞The room temperature resistivity of sample E-1 and the carrier concentration and carrier mobility at room temperature obtained by Hall measurement are 0.012 Ω･cm, 1.5×10¹⁸ cm^-3 , and 347 cm² /V･s, respectively. ＜Impurity Concentration＞

以動態二次離子質譜術（SIMS，secondary ion mass spectrometry）測量樣本E-1的雜質濃度，結果Ge濃度為1.4×10¹⁸atoms/cm³、Si濃度為7.0×10¹⁷atoms/cm³、O濃度為6.8×10¹⁵atoms/cm³，H、Cl及C的濃度低於檢測下限。該SIMS測量中的檢測下限濃度，Ge為1×10¹⁵atoms/cm³，Si為5×10¹⁴atoms/cm³，O為4×10¹⁵atoms/cm³，H（氫）為2×10¹⁶atoms/cm³，Cl（氯）為1×10¹⁴atoms/cm³，C（碳）為3×10¹⁵atoms/cm³。4.2. 實驗2The impurity concentration of sample E-1 was measured by dynamic secondary ion mass spectrometry (SIMS). The results showed that the Ge concentration was 1.4×10¹⁸ atoms/cm³ , the Si concentration was 7.0×10¹⁷ atoms/cm³ , the O concentration was 6.8×10¹⁵ atoms/cm³ , and the concentrations of H, Cl, and C were below the detection limit. The detection limit concentrations in the SIMS measurement are 1×10¹⁵ atoms/cm³ for Ge, 5×10¹⁴ atoms/cm³ for Si, 4×10¹⁵ atoms/cm³ for O, 2×10¹⁶ atoms/cm³ for H (hydrogen), 1×10¹⁴ atoms/cm³ for Cl (chlorine), and 3×10¹⁵ atoms/cm³ for C (carbon). 4.2. Experiment 2

作為晶種，係由下述GaN結晶所製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中所製作之第二c面GaN晶圓相同之結晶品質、Ga極性面的面積約為6 cm²且厚度0.4 mm的c面GaN晶圓成長而得。在該晶種的Ga極性面上，使用與實驗1中所使用者相同的氣相成長裝置，以HVPE使GaN厚膜成長。程序大致如下所述。首先，在氣相成長裝置的載台上設置晶種。不使用邊緣遮罩。接著，一邊以使N₂、H₂及NH₃的分壓分別為0.67 atm、0.31 atm及0.02 atm的方式將其供給至反應器內，一邊以設於反應器外側的加熱器將反應器內加熱。The seed crystal was prepared from the following GaN crystal: the GaN crystal was grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents to obtain a c-plane GaN wafer having the same crystal quality as the second c-plane GaN wafer prepared in Experiment 1, with an area of the Ga polar surface of about 6 cm² and a thickness of 0.4 mm. On the Ga polar surface of the seed crystal, a GaN thick film was grown by HVPE using the same vapor phase growth device as used in Experiment 1. The procedure is roughly as follows. First, a seed crystal is set on the stage of the vapor phase growth device. No edge mask is used. Next, while N₂ , H₂ , and NH₃ were supplied into the reactor so that their partial pressures were 0.67 atm, 0.31 atm, and 0.02 atm, respectively, the reactor interior was heated by a heater installed outside the reactor.

載台溫度到達1000 ℃後，使載台溫度保持一定，而使GaN成長。Ga儲存槽的溫度設定為900 ℃。成長時供給至反應器內的載子氣體，以莫耳比計，H₂為69 %，而剩餘部分為N₂。成長開始後60分鐘內，以使GaCl及NH₃的分壓分別為7.9×10^-3atm及2.4×10^-2atm的方式將其供給至反應器內，不蓄意供給摻雜氣體。After the stage temperature reached 1000°C, the stage temperature was kept constant to grow GaN. The temperature of the Ga storage tank was set to 900°C. The carrier gas supplied to the reactor during growth was 69%_H2 and the remainder_N2 in molar ratio. Within 60 minutes after the start of growth, GaCl and_NH3 were supplied to the reactor in such a way that the partial pressures were 7.9×^10-3 atm and 2.4×^10-2 atm, respectively, and no doping gas was intentionally supplied.

成長開始60分鐘後，開始對反應器內供給SiH₂Cl₂。花費5分鐘逐漸增加SiH₂Cl₂的供給速率。SiH₂Cl₂的供給速率到達既定值後，以使GaCl、NH₃及SiH₂Cl₂的分壓分別為7.9×10^-3atm、2.4×10^-2atm及1.9×10^-8atm的方式將其供給至反應器內，使摻雜Si的GaN厚膜成長約2.38 mm。從厚度與成長時間算出的摻雜Si之GaN厚膜的成長速率為40 μm/h。60 minutes after the start of growth, SiH₂ Cl₂ was supplied to the reactor. The supply rate of SiH₂ Cl₂ was gradually increased over 5 minutes. After the supply rate of SiH₂ Cl₂ reached the predetermined value, GaCl, NH₃ and SiH₂ Cl₂ were supplied to the reactor in such a way that the partial pressures were 7.9×10^-3 atm, 2.4×10^-2 atm and 1.9×10^-8 atm, respectively, so that the Si-doped GaN thick film grew to about 2.38 mm. The growth rate of the Si-doped GaN thick film calculated from the thickness and growth time was 40 μm/h.

接著，與c面平行地切割該摻雜Si之GaN厚膜，對於所得之晶圓的Ga極性面，實施以研削所進行之平坦化，之後進行CMP加工。以蝕刻去除該晶圓的N極性面側的切割損傷。再者，藉由裁切晶圓，完成厚度335 μm、主面的面積約6 cm²的摻雜Si之c面GaN晶圓（以下亦稱為「樣本E-2」）。Next, the Si-doped GaN thick film was cut parallel to the c-plane, and the Ga-polar surface of the resulting wafer was flattened by grinding, followed by CMP processing. Cutting damage on the N-polar surface side of the wafer was removed by etching. Furthermore, by cutting the wafer, a Si-doped c-plane GaN wafer with a thickness of 335 μm and a main surface area of approximately 6^cm2 was completed (hereinafter also referred to as "sample E-2").

在Ga極性面上從邊緣離開的位置，與實驗1相同地進行樣本E-2的（004）XRD搖擺曲線測量，結果其FWHM為10.0 arcsec。樣本E-2的室溫電阻率、以霍爾測量求得之室溫中的載子濃度及載子移動度分別為0.013 Ω･cm、1.3×10¹⁸cm^-3及391 cm²/V･s。The (004) XRD swing curve of sample E-2 was measured at a position away from the edge on the Ga polar plane in the same manner as in Experiment 1. The FWHM was 10.0 arcsec. The room temperature resistivity, carrier concentration at room temperature obtained by Hall measurement, and carrier mobility of sample E-2 were 0.013 Ω･cm, 1.3×10¹⁸ cm^-3 , and 391 cm² /V･s, respectively.

以動態SIMS測量樣本E-2的雜質濃度，結果Si濃度為1.4×10¹⁸atoms/cm³，而O（氧）、H（氫）、Cl（氯）及C（碳）的濃度低於檢測下限。該SIMS測量中的檢測下限濃度，Si為5×10¹⁴atoms/cm³，O為4×10¹⁵atoms/cm³，H為2×10¹⁶atoms/cm³，Cl為1×10¹⁴atoms/cm³，C為3×10¹⁵atoms/cm³。樣本E-2中，Si以外之施體雜質的總濃度低於Si濃度的1 %，載子濃度為Si濃度的93 %。4.3. 實驗3The impurity concentration of sample E-2 was measured by dynamic SIMS. The result showed that the Si concentration was 1.4×10¹⁸ atoms/cm³ , while the concentrations of O (oxygen), H (hydrogen), Cl (chlorine), and C (carbon) were below the detection limit. The detection limit concentrations in the SIMS measurement were 5×10¹⁴ atoms/cm³ for Si, 4×10¹⁵ atoms/cm³ for O, 2×10¹⁶ atoms/cm³ for H, 1×10¹⁴ atoms/cm³ for Cl, and 3×10¹⁵ atoms/cm³ for C. In sample E-2, the total concentration of donor impurities other than Si was less than 1% of the Si concentration, and the carrier concentration was 93% of the Si concentration. 4.3. Experiment 3

作為晶種，係由下述GaN結晶製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中製作之第二c面GaN晶圓相同結晶品質、Ga極性面的面積約33 cm²且厚度0.4 mm的c面GaN晶圓成長而得。在該晶種的Ga極性面上，使用與實驗1中所使用者同型的氣相成長裝置，以HVPE使GaN厚膜成長。程序大致如下所記載。首先，在氣相成長裝置的載台上設置晶種，並且以高度6 mm的石墨製邊緣遮罩圍住晶種的周圍。邊緣遮罩與晶種的邊緣密合。The seed crystal is made from the following GaN crystal: the GaN crystal is obtained by growing a c_- plane GaN wafer having the same crystal quality as the second c-plane GaN wafer produced in Experiment 1, with an area of about 33^cm2 of the Ga polar surface and a thickness of 0.4 mm by the ammonothermal method using_NH4F and NH4I as mineralizing agents. On the Ga polar surface of the seed crystal, a GaN thick film is grown by HVPE using the same type of vapor phase growth device as used in Experiment 1. The procedure is roughly as described below. First, a seed crystal is set on the carrier of the vapor phase growth device, and the seed crystal is surrounded by a graphite edge mask with a height of 6 mm. The edge mask is in close contact with the edge of the seed crystal.

接著，一邊以使N₂、H₂及NH₃的分壓分別為0.73 atm、0.24 atm及0.024 atm的方式將其供給至反應器內，一邊以設於反應器外側的加熱器將反應器內加熱。載台溫度到達1000 ℃後，使載台溫度保持一定，而使GaN成長。Ga舟的溫度設定為900 ℃。成長時供給至反應器內的載子氣體，以莫耳比計，H₂為75 %，剩餘部分為N₂。Next,_N2 ,_H2 , and_NH3 were supplied to the reactor at partial pressures of 0.73 atm, 0.24 atm, and 0.024 atm, respectively, while the reactor was heated by a heater installed outside the reactor. After the stage temperature reached 1000°C, the stage temperature was kept constant to grow GaN. The temperature of the Ga boat was set to 900°C. During the growth, the carrier gas supplied to the reactor was 75%_H2 and the remainder_N2 in terms of molar ratio.

成長開始後60分鐘內，以使GaCl及NH₃的分壓分別為7.9×10^-3atm及2.4×10^-2atm的方式將其供給至反應器內，不蓄意供給摻雜氣體。成長開始60分鐘後，開始對反應器內供給SiH₂Cl₂。花費5分鐘逐漸增加SiH₂Cl₂的供給速率。SiH₂Cl₂的供給速率到達既定值後，以使GaCl、NH₃及SiH₂Cl₂的分壓分別為7.9×10^-3atm、2.4×10^-2atm及1.6×10^-3atm的方式將其供給至反應器內，使摻雜Si的GaN厚膜成長約2 mm。從厚度與成長時間算出的摻雜Si之GaN厚膜的成長速率為35 μm/h。Within 60 minutes after the start of growth, GaCl and NH₃ were supplied to the reactor in such a way that the partial pressures were 7.9×10^-3 atm and 2.4×10^-2 atm, respectively, and no doping gas was intentionally supplied. 60 minutes after the start of growth, SiH₂ Cl₂ was supplied to the reactor. The supply rate of SiH₂ Cl₂ was gradually increased over 5 minutes. After the supply rate of SiH₂ Cl₂ reached the predetermined value, GaCl, NH₃ and SiH₂ Cl₂ were supplied to the reactor in such a way that the partial pressures were 7.9×10^-3 atm, 2.4×10^-2 atm and 1.6×10^-3 atm, respectively, and the Si-doped GaN thick film grew to about 2 mm. The growth rate of the Si-doped GaN thick film calculated from the thickness and growth time is 35 μm/h.

接著，與c面平行地切割已成長的GaN厚膜，對於所得之晶圓的Ga極性面，實施以研削所進行之平坦化，之後進行CMP加工。以蝕刻去除該晶圓的N極性面側的切割損傷。再者，藉由裁切晶圓，完成厚度360 μm、主面的面積約30 cm²的摻雜Si之c面GaN基板（以下亦稱為「樣本E-3」）。Next, the grown GaN thick film was cut parallel to the c-plane, and the Ga-polar surface of the resulting wafer was flattened by grinding, followed by CMP processing. Cutting damage on the N-polar surface side of the wafer was removed by etching. Furthermore, by cutting the wafer, a Si-doped c-plane GaN substrate with a thickness of 360 μm and a main surface area of approximately 30^cm2 was completed (hereinafter also referred to as "sample E-3").

在樣本E-3的Ga極性面側測量（004）XRD搖擺曲線。首先，沿著通過Ga極性面的略中央而與m軸垂直的1條線，於長度40 mm中每隔1 mm即進行ω掃描，藉此得到在該線上以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。從與GaN結晶的m軸垂直的方向將X射線射入試片，除此之外，各測量點中的測量條件與實驗1相同。40個測量點之間的（004）XRD搖擺曲線FWHM的最大值為19.3 arcsec，平均值為10.5 arcsec。The (004) XRD swing curve was measured on the Ga polar surface side of sample E-3.First, ω scanning was performed every 1 mm along a line passing through the approximate center of the Ga polar surface and perpendicular to the m-axis in a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points arranged at 1 mm intervals on the line. The measurement conditions at each measurement point were the same as those in Experiment 1, except that X-rays were irradiated into the specimen in a direction perpendicular to the m-axis of the GaN crystal.The maximum value of the FWHM of the (004) XRD swing curve between the 40 measurement points was 19.3 arcsec, and the average value was 10.5 arcsec.

接著，沿著通過Ga極性面的略中央而與a軸垂直的1條線，於長度40 mm中每隔1 mm即進行ω掃描，藉此得到在該線上以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。各測量點中的測量條件與實驗1相同。40個測量點之間的（004）XRD搖擺曲線FWHM的最大值為16.2 arcsec，平均值為10.4 arcsec。在Ga極性面之中央測量的樣本E-3的載子濃度為1.5×10¹⁸cm^-3。4.4. 實驗4Next, along a line passing through the approximate center of the Ga polar surface and perpendicular to the a-axis, ω scanning was performed every 1 mm in a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points arranged at a pitch of 1 mm on the line. The measurement conditions at each measurement point were the same as those in Experiment 1. The maximum value of the FWHM of the (004) XRD swing curve between the 40 measurement points was 16.2 arcsec, and the average value was 10.4 arcsec. The carrier concentration of sample E-3 measured at the center of the Ga polar surface was 1.5×10¹⁸ cm^-3 . 4.4. Experiment 4

作為晶種，係由下述GaN結晶製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中製作的第二c面GaN晶圓相同的結晶品質、Ga極性面的面積約32 cm²且厚度0.56 mm的c面GaN晶圓成長而得。在該晶種的Ga極性面上，使用實驗1中所使用者同型的氣相成長裝置，以HVPE使GaN厚膜成長。程序大致如下所記載。首先，在氣相成長裝置的載台上設置晶種，並且以高度4 mm的石墨製邊緣遮罩覆蓋晶種的邊緣及Ga極性面的外周部。The seed crystal was prepared from the following GaN crystal: the GaN crystal was grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents to form a c-plane GaN wafer having the same crystal quality as the second c-plane GaN wafer produced in Experiment 1, with an area of about 32 cm² of the Ga polar surface and a thickness of 0.56 mm. On the Ga polar surface of the seed crystal, a GaN thick film was grown by HVPE using the same type of vapor phase growth device used in Experiment 1. The procedure is roughly as follows. First, a seed crystal was set on the stage of the vapor phase growth device, and the edge of the seed crystal and the outer periphery of the Ga polar surface were covered with a graphite edge mask with a height of 4 mm.

接著，一邊以使N₂、H₂及NH₃的分壓分別為0.30 atm、0.65 atm及0.052 atm的方式將其供給至反應器內，一邊以設於反應器外側的加熱器將反應器內加熱。在載台溫度到達960 ℃時，開始GaN的成長。從成長開始10分鐘後，開始對於反應器內供給SiH₂Cl₂。花費30分鐘逐漸增加SiH₂Cl₂的供給速率。Next,_N2 ,_H2 , and_NH3 were supplied to the reactor at partial pressures of 0.30 atm, 0.65 atm, and 0.052 atm, respectively, while the reactor was heated by a heater installed outside the reactor. When the stage temperature reached 960°C, GaN growth began. Ten minutes after the start of growth,_SiH2Cl2 was_supplied to the reactor. The supply rate_ofSiH2Cl2 was gradually increased over 30 minutes.

成長開始後到經過3小時為止的成長條件，係鎵儲存槽溫度800 ℃、載台溫度960 ℃、GaCl分壓6.0×10^-3atm、NH₃分壓4.1×10^-2atm、SiH₂Cl₂分壓2.1×10^-8atm。3小時過後，將載台溫度上升至998 ℃。供給至反應器內的載子氣體，以莫耳比計，H₂為40 %，剩餘部分為N₂。如此，使摻雜Si的GaN厚膜成長約2.2 mm的厚度。成長速率為37 μm/h。The growth conditions from the start of growth until 3 hours were: Ga storage tank temperature 800 °C, stage temperature 960 °C, GaCl partial pressure 6.0×10^-3 atm, NH₃ partial pressure 4.1×10^-2 atm, SiH₂ Cl₂ partial pressure 2.1×10^-8 atm. After 3 hours, the stage temperature was raised to 998 °C. The carrier gas supplied to the reactor was 40% H₂ and the remainder N₂ in molar ratio. In this way, the Si-doped GaN thick film grew to a thickness of about 2.2 mm. The growth rate was 37 μm/h.

接著，與c面平行地切割已成長的GaN厚膜，對於所得之晶圓的Ga極性面，實施以研削所進行之平坦化，之後進行CMP加工。以蝕刻去除該晶圓的N極性面側的切割損傷。再者，藉由裁切晶圓，完成厚度400 μm、主面的面積約16 cm²的c面GaN晶圓（以下亦稱為「樣本E-4」）。Next, the grown GaN thick film was cut parallel to the c-plane, and the Ga polar surface of the resulting wafer was flattened by grinding, followed by CMP processing. Cutting damage on the N polar surface side of the wafer was removed by etching. Furthermore, by cutting the wafer, a c-plane GaN wafer with a thickness of 400 μm and a main surface area of approximately 16^cm2 was completed (hereinafter also referred to as "sample E-4").

在樣本E-4的Ga極性面側測量（004）XRD搖擺曲線。沿著通過Ga極性面之中央而與m軸垂直的1條線，於長度40 mm中每隔1 mm即進行ω掃描，藉此得到在該線上以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。從與GaN結晶的m軸垂直的方向將X射線射入試片，除此之外，各測量點中的測量條件與實驗1相同。40個測量點之間的（004）XRD搖擺曲線FWHM的最大值為17.8 arcsec，平均值為11.2 arcsec。(004) XRD swing curve measured on the Ga polar surface side of sample E-4.A line passing through the center of the Ga polar surface and perpendicular to the m-axis was scanned at ω intervals of 1 mm over a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points arranged at 1 mm intervals on the line. The measurement conditions at each measurement point were the same as those in Experiment 1, except that X-rays were irradiated into the specimen in a direction perpendicular to the m-axis of the GaN crystal.The maximum value of the FWHM of the (004) XRD swing curve between the 40 measurement points was 17.8 arcsec, and the average value was 11.2 arcsec.

Ga極性面之中央測量的樣本E-4的載子濃度為1.5×10¹⁸cm^-3。增加SiH₂Cl₂的供給量，除此之外，使用與使樣本E-4成長時約略相同的條件，可使結晶品質與樣本E-4相同、Ga極性面之中央的載子濃度為2.8×10¹⁸cm^-3的c面GaN基板成長。4.5. 實驗5The carrier concentration of sample E-4 measured at the center of the Ga polar surface is 1.5×10¹⁸ cm^-3 . By increasing the amount of SiH₂ Cl₂ supplied, using conditions approximately the same as those used to grow sample E-4, a c-plane GaN substrate with the same crystal quality as sample E-4 and a carrier concentration of 2.8×10¹⁸ cm^-3 at the center of the Ga polar surface can be grown. 4.5. Experiment 5

作為晶種，係由下述GaN結晶製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中製作的第二c面GaN晶圓相同的結晶品質、Ga極性面的面積約33.8 cm²且厚度0.55 mm的c面GaN晶圓成長而得。在該晶種的Ga極性面上，使用與實驗1中所使用者同型的氣相成長裝置，以HVPE使GaN厚膜成長。程序大致如下所記載。首先，在氣相成長裝置的載台上設置晶種，並且以高度4 mm的石墨製邊緣遮罩覆蓋晶種的邊緣及Ga極性面的外周部。The seed crystal was prepared from the following GaN crystal: the GaN crystal was grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents to form a c-plane GaN wafer having the same crystal quality as the second c-plane GaN wafer produced in Experiment 1, with an area of the Ga polar surface of about 33.8 cm² and a thickness of 0.55 mm. On the Ga polar surface of the seed crystal, a GaN thick film was grown by HVPE using the same type of vapor phase growth device as used in Experiment 1. The procedure is roughly as follows. First, a seed crystal was set on the stage of the vapor phase growth device, and the edge of the seed crystal and the outer periphery of the Ga polar surface were covered with a graphite edge mask with a height of 4 mm.

接著，一邊以使N₂、H₂及NH₃的分壓分別為0.30 atm、0.65 atm及0.052 atm的方式將其供給至反應器內，一邊以設於反應器外側的加熱器將反應器內加熱。載台溫度到達1005 ℃時，開始GaN的成長。成長條件，係鎵儲存槽溫度800 ℃、載台溫度1005℃、GaCl分壓9.0×10^-3atm、NH₃分壓4.1×10^-2atm，供給至反應器內的載子氣體，以莫耳比計，H₂為38 %，剩餘部分為N₂。Next,_N2 ,_H2 and_NH3 were supplied to the reactor at partial pressures of 0.30 atm, 0.65 atm and 0.052 atm respectively, while the reactor was heated by a heater installed outside the reactor. When the stage temperature reached 1005°C, GaN growth began. The growth conditions were a gallium storage tank temperature of 800°C, a stage temperature of 1005°C, a GaCl partial pressure of 9.0×^10-3 atm, and an NH3_partial pressure of 4.1×^10-2 atm. The carrier gas supplied to the reactor was 38%_H2 and the remainder_N2 in terms of molar ratio.

再者，成長開始5小時後，開始對反應器內供給GeCl₄。花費30分鐘將GeCl₄分壓逐漸增加至1.9×10^-7atm，之後使其為定值。如此，使摻雜Ge的GaN厚膜成長約3 mm的厚度。成長速率為47 μm/h。Furthermore, 5 hours after the start of growth, GeCl₄ was supplied to the reactor. The partial pressure of GeCl₄ was gradually increased to 1.9×10^-7 atm over 30 minutes and then kept constant. In this way, the Ge-doped GaN thick film grew to a thickness of about 3 mm. The growth rate was 47 μm/h.

接著，與c面平行地切割已成長的GaN厚膜，對於所得之晶圓的Ga極性面，實施以研削所進行之平坦化，之後進行CMP加工。以蝕刻去除該晶圓的N極性面側的切割損傷。再者，藉由裁切晶圓，完成厚度400 μm、主面的面積約19.5 cm²的c面GaN晶圓（以下亦稱為「樣本E-5」）。Next, the grown GaN thick film was cut parallel to the c-plane, and the Ga polar surface of the resulting wafer was flattened by grinding, followed by CMP processing. Cutting damage on the N polar surface side of the wafer was removed by etching. Furthermore, by cutting the wafer, a c-plane GaN wafer with a thickness of 400 μm and a main surface area of approximately 19.5^cm2 was completed (hereinafter also referred to as "sample E-5").

在樣本E-5的Ga極性面側測量（004）XRD搖擺曲線。首先，沿著通過Ga極性面之中央而與m軸垂直的1條線，於長度40 mm中每隔1 mm即進行ω掃描，藉此得到在該線上以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。從與GaN結晶的m軸垂直的方向將X射線射入試片，除此之外，各測量點中的測量條件與實驗1相同。40個測量點之間的（004）XRD搖擺曲線FWHM的最大值為9.4 arcsec，平均值為7.5 arcsec。The (004) XRD swing curve was measured on the Ga polar surface side of sample E-5.First, ω scanning was performed every 1 mm along a line passing through the center of the Ga polar surface and perpendicular to the m-axis in a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points arranged at 1 mm intervals on the line. The measurement conditions at each measurement point were the same as those in Experiment 1, except that X-rays were irradiated into the specimen in a direction perpendicular to the m-axis of the GaN crystal.The maximum value of the FWHM of the (004) XRD swing curve between the 40 measurement points was 9.4 arcsec, and the average value was 7.5 arcsec.

接著，沿著通過Ga極性面的略中央而與a軸垂直的1條線，於長度40 mm中每隔1 mm即進行ω掃描，藉此得到在該線上以1 mm間距排列的40個測量點的（004）XRD搖擺曲線。各測量點中的測量條件與實驗1相同。在40個測量點之間的（004）XRD搖擺曲線FWHM的最大值為11.0 arcsec，平均值為7.9 arcsec。Ga極性面之中央測量的樣本E-5的載子濃度為4.9×10¹⁸cm^-3。Next, along a line passing through the approximate center of the Ga polar surface and perpendicular to the a-axis, ω scanning was performed every 1 mm in a length of 40 mm, thereby obtaining the (004) XRD swing curve of 40 measurement points arranged at 1 mm intervals on the line. The measurement conditions at each measurement point were the same as those in Experiment 1. The maximum value of the FWHM of the (004) XRD swing curve between the 40 measurement points was 11.0 arcsec, and the average value was 7.9 arcsec. The carrier concentration of sample E-5 measured at the center of the Ga polar surface was 4.9×10¹⁸ cm^-3 .

再者，使用光致發光（PL，Photoluminescence）成像裝置［PHOTON Design(股)製PLI-200］，計算樣本E-5之Ga極性面上的多個測量點中，在230 μm×230 μm的正方形區域內觀察到的PL影像中的暗點數量。以水銀燈為激發源、以激發波長313 nm、檢測波長365±5 nm這樣的條件取得PL影像。檢測器為2048×2048像素的CMOS相機，因此像素解析能力約為0.11 μm。複數的測量點，係位於一邊2.88 mm之正方形格子的格點，其數量為381個。381個測量點之間的暗點密度平均為3.3×10⁴cm^-2，未觀察到暗點的測量點數量高達整體的54 %。算出平均值時，未觀察到暗點之測量點中的暗點密度為0 cm^-2，僅觀察到1個暗點的測量點中的差排密度，在每230×230 μm²中為1個，因此為1.9×10³cm^-2。在以PL成像測量上述的暗點密度之後，以加熱至270 ℃的濃度89 %的硫酸將樣本E-5蝕刻1小時，在其Ga極性面上形成的蝕刻凹槽與PL影像的暗點1對1對應。本案發明人等另外確認以該方法所形成之蝕刻凹槽，亦與陰極發光影像中出現的暗點1對1對應。Furthermore, the number of dark spots in the PL image observed in a square area of 230 μm×230 μm at multiple measurement points on the Ga polar surface of sample E-5 was calculated using a photoluminescence (PL) imaging device [PLI-200 manufactured by PHOTON Design Co., Ltd.]. The PL image was acquired under the conditions of a mercury lamp as the excitation source, an excitation wavelength of 313 nm, and a detection wavelength of 365±5 nm. The detector was a 2048×2048 pixel CMOS camera, so the pixel resolution was approximately 0.11 μm. The multiple measurement points were 381 points located on a square grid of 2.88 mm on one side. The average dark spot density between the 381 measurement points was 3.3×10⁴ cm^-2 , and the number of measurement points where no dark spots were observed was as high as 54% of the total. When the average value is calculated, the dark spot density in the measurement point where no dark spots are observed is 0 cm^-2 , and the dislocation density in the measurement point where only one dark spot is observed is 1 in every 230×230 μm² , so it is 1.9×10³ cm^-2 . After measuring the above dark spot density by PL imaging, the sample E-5 was etched for 1 hour with sulfuric acid with a concentration of 89% heated to 270°C, and the etched grooves formed on its Ga polar surface corresponded one to one with the dark spots in the PL image. The inventors of this case also confirmed that the etched grooves formed by this method also corresponded one to one with the dark spots appearing in the cathodoluminescence image.

在從上述的摻雜Ge之厚度約3 mm的GaN厚膜同時切割出樣本E-5，經過與樣本E-5相同的加工而完成的厚度400 μm、主面的面積約20 cm²的c面GaN晶圓中的主平面中，調查切割角的變動。選擇與a面之一平行的方向作為x方向，並使與x方向垂直的方向為y方向，此時在通過Ga極性面之中心而在x方向上延伸的長度4 cm的線上，切割角之x方向分量的變動幅度為0.04度（中間值±0.02度），在通過Ga極性面之中心而在y方向上延伸的長度4 cm的線上，切割角之y方向分量的變動幅度為0.06度（中間值±0.03度）。4.6. 實驗6Sample E-5 was cut from the aforementioned Ge-doped GaN thick film with a thickness of about 3 mm. The variation of the cut angle was investigated in the main plane of a c-plane GaN wafer with a thickness of 400 μm and a main surface area of about 20^cm2 , which was processed in the same manner as sample E-5. The direction parallel to one of the a-planes was selected as the x-direction, and the direction perpendicular to the x-direction was selected as the y-direction. At this time, the variation range of the x-direction component of the cut angle on a line with a length of 4 cm extending in the x-direction through the center of the Ga polar surface was 0.04 degrees (median value ±0.02 degrees), and the variation range of the y-direction component of the cut angle on a line with a length of 4 cm extending in the y-direction through the center of the Ga polar surface was 0.06 degrees (median value ±0.03 degrees). 4.6. Experiment 6

作為晶種，係由下述GaN結晶製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中製作的第二c面GaN晶圓相同結晶品質的c面GaN晶圓成長而得。該晶種的Ga極性主面上，使用與實驗1中使用者同型的氣相成長裝置，以不同的條件，以HVPE使GaN結晶成長，藉此製作樣本E-6a~E-6e。The seed crystal was made from the following GaN crystal: the GaN crystal was grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents to form a c-plane GaN wafer with the same crystal quality as the second c-plane GaN wafer produced in Experiment 1. On the Ga polar primary surface of the seed crystal, GaN crystals were grown by HVPE under different conditions using the same type of vapor phase growth device as that used in Experiment 1, thereby producing samples E-6a~E-6e.

以HVPE使GaN結晶成長時，載台溫度約1000 ℃，Ga儲存槽的溫度為800 ℃，供給至反應器內的載子氣體中，以莫耳比計，H₂為69 %，剩餘部分為N₂。關於樣本E-6a~E-6e的任一者，晶種上最初成長的第一層，皆係以成長速率約40 μm/h所形成。When GaN is crystallized and grown by HVPE, the stage temperature is about 1000°C, the temperature of the Ga storage tank is 800°C, and the carrier gas supplied to the reactor is 69% H₂ in molar ratio, and the remainder is N_2. For any of the samples E-6a~E-6e, the first layer initially grown on the seed crystal is formed at a growth rate of about 40 μm/h.

樣本E-6a係僅使第一層在晶種上成長。樣本E-6b，係在第一層的成長後，接著以成長速率80 μm/h使厚度40 μm的第二層成長，藉此進行製作。樣本E-6c，係在第一層的成長後，接著以成長速率120 μm/h使厚度40 μm的第二層成長，藉此進行製作。樣本E-6d，係在第一層的成長後，接著使用SiH₂Cl₂（二氯矽烷），使摻雜Si的厚度21 μm的第二層成長，藉此進行製作。樣本E-6e，係在第一層的成長後，接著使用GeCl₄（四氯化鍺），使摻雜Ge的厚度21 μm的第二層成長，藉此進行製作。Sample E-6a was produced by growing only the first layer on the seed crystal. Sample E-6b was produced by growing the first layer and then growing a second layer with a thickness of 40 μm at a growth rate of 80 μm/h. Sample E-6c was produced by growing the first layer and then growing a second layer with a thickness of 40 μm at a growth rate of 120 μm/h. Sample E-6d was produced by growing the first layer and then growing a second layer with a thickness of 21 μm doped with Si using SiH₂ Cl₂ (dichlorosilane). Sample E-6e was produced by growing a Ge-doped second layer with a thickness of 21 μm using GeCl₄ (germanium tetrachloride) after the first layer was grown.

製作各樣本時以HVPE進行GaN結晶的成長條件如下表2所示。The growth conditions of GaN crystals by HVPE when making various samples are shown in Table 2 below.

[表2][Table 2]

樣本E-6a~E-6e的任一者中，在晶種上以HVPE成長的GaN結晶之頂面，在肉眼觀察下為鏡面平坦。以螢光顯微鏡觀察樣本E-6d及E-6e的剖面時，第一層與第二層之界面的平坦性良好。以拉曼分光法評估樣本E-6d及E-6e的第二層之載子濃度，皆為1×10¹⁸cm^-3。In any of the samples E-6a~E-6e, the top surface of the GaN crystal grown by HVPE on the seed crystal is mirror flat under naked eye observation. When the cross-section of samples E-6d and E-6e is observed by a fluorescent microscope, the flatness of the interface between the first layer and the second layer is good. The carrier concentration of the second layer of samples E-6d and E-6e evaluated by Raman spectroscopy is 1×10¹⁸ cm^-3 .

使用多光子激發顯微鏡（Nikon股份有限公司製　高速多光子共焦點雷射顯微鏡系統　A1R-MP+），分別從第十四圖所示HVPE-GaN結晶的表面側觀察樣本E-6a~E-6e的三光子激發像（3PPL像）（其中，樣本E-6a無第二層）。激發源係使用波長800 nm的Ti-藍寶石鎖模雷射（mode-locked laser），以脈衝寬度140 fs及重複頻率80 MHz進行驅動。Using a multiphoton excitation microscope (Nikon Co., Ltd., High-speed Multiphoton Confocal Laser Microscope System A1R-MP+), three-photon excitation images (3PPL images) of samples E-6a~E-6e were observed from the surface side of the HVPE-GaN crystal shown in Figure 14 (sample E-6a does not have a second layer). The excitation source is a Ti-sapphire mode-locked laser with a wavelength of 800 nm, driven with a pulse width of 140 fs and a repetition frequency of 80 MHz.

從3PPL像觀察，可得知以下事項。樣本E-6a的第一層中存在的線差排，係僅從晶種傳遞而來。在晶種與第一層的界面中，另外在第一層的途中，皆未確認到新的線差排產生。樣本E-6b中，第一層的線差排未在第一層與第二層的界面分支，而傳遞至第二層。未確認到第二層的途中產生新的線差排。樣本E-6c中，與樣本E-6b不同，從第一層傳遞至第二層的線差排皆在第一層與第二層的界面進行二分支。亦即，第二層中線差排的數量為第一層的2倍。From the observation of 3PPL images, the following can be known.The line dislocations existing in the first layer of sample E-6a are only transferred from the seed crystal. No new line dislocations are confirmed to be generated at the interface between the seed crystal and the first layer, and also in the middle of the first layer.In sample E-6b, the line dislocations of the first layer are not branched at the interface between the first layer and the second layer, but are transferred to the second layer. No new line dislocations are confirmed to be generated in the middle of the second layer.In sample E-6c, unlike sample E-6b, the line dislocations transferred from the first layer to the second layer are all branched at the interface between the first layer and the second layer. That is, the number of line dislocations in the second layer is twice that of the first layer.

樣本E-6d中，一部分的線差排從第一層傳遞至第二層時，在第一層與第二層的界面進行二分支，但這種線差排的比例，在100個中約一個左右。未確認到在第二層的途中產生新的線差排。樣本E-6e中，一部分的線差排在從第一層傳遞至第二層時，在第一層與第二層的界面進行二分支，這種線差排的比例，在50個中約一個左右。未確認到在第二層的途中產生新的線差排。這種樣本E-6d及E-6e的3PPL觀察結果，暗示Si或Ge的摻雜對於線差排密度幾乎沒有影響。4.7. 實驗7In sample E-6d, part of the line dislocations branched at the interface between the first and second layers when they were transferred from the first layer to the second layer, but the proportion of such line dislocations was about one in 100. No new line dislocations were confirmed to be generated on the way to the second layer.In sample E-6e, part of the line dislocations branched at the interface between the first and second layers when they were transferred from the first layer to the second layer, and the proportion of such line dislocations was about one in 50. No new line dislocations were confirmed to be generated on the way to the second layer.The 3PPL observation results of samples E-6d and E-6e suggest that doping with Si or Ge has almost no effect on the line dislocation density.4.7. Experiment 7

作為晶種，係由下述GaN結晶製作：該GaN結晶，係使用NH₄F與NH₄I作為礦化劑，以氨熱法使具有與實驗1中製作的第二c面GaN晶圓相同的結晶品質、Ga極性面的面積約24.8 cm²且厚度0.53 mm的c面GaN晶圓成長而得。該GaN結晶的製造過程中，使用形成線寬20 μm之線狀開口傾斜之方形格子圖案的選擇成長遮罩。傾斜的方形格子圖案，係將分別與a面平行且互相成為60度角的2個條紋圖案重疊而成，2個條紋圖案中，一個間距為2 mm，另一個間距為15 mm。在該晶種的Ga極性面上，使用與實驗1中所使用者同型的氣相成長裝置，以HVPE使GaN厚膜成長。程序大致如下所記載。首先，在氣相成長裝置的載台上設置晶種，並且以高度4 mm的石墨製邊緣遮罩覆蓋晶種的邊緣及Ga極性面的外周部。The seed crystal was made from the following GaN crystal: the GaN crystal was grown by the ammonothermal method using NH₄ F and NH₄ I as mineralizing agents, with the same crystal quality as the second c-plane GaN wafer produced in Experiment 1, with an area of Ga polarity plane of about 24.8 cm² and a thickness of 0.53 mm. In the manufacturing process of the GaN crystal, a selective growth mask was used to form a square lattice pattern with a line opening tilted with a line width of 20 μm. The tilted square lattice pattern is formed by overlapping two stripe patterns that are parallel to the a-plane and at an angle of 60 degrees to each other. The two stripe patterns have a spacing of 2 mm in one and 15 mm in the other. On the Ga polar surface of the seed crystal, a GaN thick film was grown by HVPE using the same type of vapor phase growth apparatus used in Experiment 1. The procedure is roughly as follows. First, a seed crystal was placed on the stage of the vapor phase growth apparatus, and the edge of the seed crystal and the outer periphery of the Ga polar surface were covered with a 4 mm high graphite edge mask.

接著，一邊以使N₂、H₂及NH₃的分壓分別為0.30 atm、0.65 atm及0.052 atm的方式將其供給至反應器內，一邊以設於反應器外側的加熱器將反應器內加熱。載台溫度到達1005 ℃時，開始GaN的成長。成長條件係鎵儲存槽溫度800 ℃、載台溫度1005 ℃、GaCl分壓9.2×10^-3atm、NH₃分壓4.2×10^-2atm，供給至反應器內的載子氣體，以莫耳比計，H₂為40 %，剩餘部分為N₂。Next,_N2 ,_H2 , and_NH3 were supplied to the reactor at partial pressures of 0.30 atm, 0.65 atm, and 0.052 atm, respectively, while the reactor was heated by a heater installed outside the reactor. When the stage temperature reached 1005°C, GaN growth began. The growth conditions were a gallium storage tank temperature of 800°C, a stage temperature of 1005°C, a GaCl partial pressure of 9.2×^10-3 atm, and an_NH3 partial pressure of 4.2×^10-2 atm. The carrier gas supplied to the reactor was 40%_H2 and the remainder_N2 in terms of molar ratio.

再者，成長開始5小時後，開始對反應器內供給GeCl₄。花費30分鐘將GeCl₄分壓逐漸增加至1.6×10^-7atm，之後使其為定值。又，成長開始5小時後，花費4小時將GaCl分壓逐漸增加至9.4×10^-3atm。如此，使摻雜Ge的GaN厚膜成長約3 mm的厚度。成長速率為43 μm/h。Furthermore, 5 hours after the start of growth, GeCl₄ was fed into the reactor. The GeCl₄ partial pressure was gradually increased to 1.6×10^-7 atm over 30 minutes and then kept constant. Also, 5 hours after the start of growth, the GaCl partial pressure was gradually increased to 9.4×10^-3 atm over 4 hours. In this way, the Ge-doped GaN thick film grew to a thickness of about 3 mm. The growth rate was 43 μm/h.

接著，與c面平行地切割已成長的GaN厚膜，在所得之晶圓的兩個主面分別實施以研削所進行之平坦化，之後進行CMP加工。再者，藉由裁切晶圓，完成厚度400 μm、主面的面積約15.2 cm²的c面GaN晶圓（以下亦稱為「樣本E-7」）。在Ga極性面之中央所測量之樣本E-7的載子濃度為2.0×10¹⁸cm^-3。Next, the grown GaN thick film was cut parallel to the c-plane, and the two main surfaces of the obtained wafer were flattened by grinding, followed by CMP processing. Furthermore, by cutting the wafer, a c-plane GaN wafer with a thickness of 400 μm and a main surface area of approximately 15.2^cm2 was completed (hereinafter also referred to as "sample E-7"). The carrier concentration of sample E-7 measured at the center of the Ga polar surface was 2.0×10¹⁸ cm^-3 .

使用X射線繞射裝置［(股)RIGAKU製高通量＆高解析度X射線形貌分析成像系統 XRTmicron］，進行樣本E-7的X射線形貌分析。利用來自（110）結晶面的繞射所得之20 mm×20 mm的正方形區域的穿透X射線形貌分析影像顯示於第十六圖。使用之X射線源為MoKα，試片的厚度為400 μm，故μ･t＝11.6。因此，該X射線形貌分析影像為異常穿透像。以往，以HVPE成長的GaN結晶所構成的m面GaN晶圓中，雖有觀察到X射線異常穿透像的例子（WO2015/020161），但本案應該是第一個提出在以HVPE成長的c面GaN晶圓中的X射線之異常穿透。若參照第十六圖，圖中可觀察到在左右方向上延伸的缺陷陣列所構成的條紋與從該條紋傾斜60度而從左下往右上方向延伸的缺陷區域。該條紋與a面平行，間距為2 mm，其反映了晶種用的c面GaN晶圓的製造過程中所使用的選擇成長遮罩的圖案。將摻雜物從Ge變更為Si，除此之外，以實質上相同的方法製作厚度350 μm的c面GaN晶圓，其亦可得到20 mm×20 mm的正方形區域的穿透X射線形貌分析影像。The X-ray morphology analysis of sample E-7 was performed using an X-ray diffraction device [RIGAKU High Throughput & High Resolution X-ray Topography Analysis Imaging System XRTmicron]. The transmission X-ray topography analysis image of a 20 mm × 20 mm square area obtained by diffraction from the (110) crystal plane is shown in Figure 16. The X-ray source used was MoKα, and the thickness of the specimen was 400 μm, so μ･t = 11.6. Therefore, the X-ray topography analysis image is an abnormal transmission image. In the past, although there have been examples of X-ray abnormal transmission images observed in m-plane GaN wafers composed of GaN crystals grown by HVPE (WO2015/020161), this case should be the first to propose abnormal transmission of X-rays in c-plane GaN wafers grown by HVPE.Referring to Figure 16, the figure shows stripes consisting of defect arrays extending in the left-right direction and defect regions extending from the lower left to the upper right at an angle of 60 degrees from the stripes. The stripes are parallel to the a-plane and have a spacing of 2 mm, which reflects the pattern of the selective growth mask used in the manufacturing process of the c-plane GaN wafer used as a seed.In addition to changing the dopant from Ge to Si, a c-plane GaN wafer with a thickness of 350 μm was produced using essentially the same method, which also obtained a 20 mm×20 mm square area of the through-X-ray morphology analysis image.

以上雖以具體的實施態樣說明本發明，但各實施態樣係提出作為一例，並未限定本發明的範圍。本說明書所記載之各實施態樣，在不脫離發明主旨的範圍內，可進行各種變形，且在可實施的範圍內，能夠與其他實施態樣所說明之特徵組合。Although the present invention is described above with specific embodiments, each embodiment is provided as an example and does not limit the scope of the present invention. Each embodiment described in this specification can be modified in various ways without departing from the scope of the invention, and can be combined with the features described in other embodiments within the scope of implementation.

10:結晶11、21:第一主面12、22:第二主面20:晶圓40:雙層晶圓41:Ga極性側的主面43:再成長界面100:HVPE裝置101:反應器102:鎵儲存槽103:載台104:第一加熱器105:第二加熱器Z₁:第一區域Z₂:第二區域P₁:氨導入管P₂:氯化氫導入管P₃:氯化鎵導入管P₄:摻雜物導入管P_E:排氣管PM:測量點DC、DW:直徑tC、tW、t1:厚度L、L1、L2:線Lf:表層Lb:底層R1:第一區域R2:第二區域Z:頂面距離h:高度10: Crystallization 11, 21: First main surface 12, 22: Second main surface 20: Wafer 40: Double-layer wafer 41: Main surface of Ga polar side 43: Re-growth interface 100: HVPE device 101: Reactor 102: Ga storage tank 103: Carrier 104: First heater 105: Second heater_Z1 : First zone_Z2 : Second zone_P1 : Ammonia inlet pipe_P2 : Hydrogen chloride inlet pipe_P3 : GaCl2 inlet pipe_P4 : Dopant inlet pipe P_E : Exhaust pipe PM: Measurement points DC, DW: Diameter tC, tW, t1: Thickness L, L1, L2: Line Lf: Surface layer Lb: Bottom layer R1: First area R2: Second area Z: Top distance h: Height

第一圖係顯示實施態樣之n型GaN結晶的立體圖。第二圖係顯示實施態樣之n型GaN結晶的俯視圖。第三圖係顯示實施態樣之n型GaN結晶的俯視圖。第四圖係顯示實施態樣之GaN晶圓的立體圖。第五圖係顯示實施態樣之GaN晶圓的剖面圖。第六圖係顯示實施態樣之GaN晶圓的俯視圖。第七圖係顯示實施態樣之GaN晶圓的俯視圖。第八圖係顯示雙層GaN晶圓之一例的立體圖。第九圖係顯示HVPE裝置之基本構成的示意面。第十（a）圖係顯示載台上設置晶種與邊緣遮罩時的剖面圖，第十（b）圖係顯示GaN結晶在第十（a）圖所示之晶種上成長之狀態的剖面圖。第十一圖係顯示在載台上設置晶種與邊緣遮罩時的剖面圖。第十二圖係顯示在以氨熱法使GaN結晶成長所使用的結晶成長裝置之基本構成的圖式。第十三圖係顯示以氨熱法在第一c面GaN晶圓的N極性面上使GaN結晶層成長時的剖面圖。第十四圖係顯示實驗6中所製作之樣本的構成與實驗6中的三光子激發像的觀察方向的圖式。第十五圖係說明c面GaN晶圓的切割角可分解成在互相垂直之2個方向的分量的圖式。第十六圖係顯示實驗7中，從以HVPE成長的GaN結晶所構成的c面GaN晶圓（樣本E-7）得到的、20 mm×20 mm的正方形區域的穿透X射線形貌分析影像（以影像代替圖式）。The first figure is a perspective view of an n-type GaN crystal of an implementation example.The second figure is a top view of an n-type GaN crystal of an implementation example.The third figure is a top view of an n-type GaN crystal of an implementation example.The fourth figure is a perspective view of a GaN wafer of an implementation example.The fifth figure is a cross-sectional view of a GaN wafer of an implementation example.The sixth figure is a top view of a GaN wafer of an implementation example.The seventh figure is a top view of a GaN wafer of an implementation example.The eighth figure is a perspective view of an example of a double-layer GaN wafer.The ninth figure is a schematic diagram showing the basic structure of an HVPE device.FIG. 10 (a) is a cross-sectional view showing a state where a seed crystal and an edge mask are set on a carrier, and FIG. 10 (b) is a cross-sectional view showing a state where a GaN crystal grows on the seed crystal shown in FIG. 10 (a).FIG. 11 is a cross-sectional view showing a state where a seed crystal and an edge mask are set on a carrier.FIG. 12 is a diagram showing a basic structure of a crystal growth device used to grow GaN crystals by an ammonothermal method.FIG. 13 is a cross-sectional view showing a state where a GaN crystal layer is grown on an N-polar surface of a first c-plane GaN wafer by an ammonothermal method.FIG. 14 is a diagram showing a structure of a sample prepared in Experiment 6 and an observation direction of a three-photon excitation image in Experiment 6.FIG. 15 is a diagram showing that the cutting angle of a c-plane GaN wafer can be decomposed into components in two directions perpendicular to each other.FIG16 shows a transmission X-ray topography analysis image of a 20 mm×20 mm square area obtained from a c-plane GaN wafer (sample E-7) composed of GaN crystals grown by HVPE in Experiment 7 (the image is used instead of the figure).

10:結晶10: Crystallization

11:第一主面11: First main surface

12:第二主面12: Second main surface

DC:直徑DC: Diameter

tC:厚度tC:Thickness

Claims (167)

Translated fromChinese

一種n型GaN結晶，其所含有之最高濃度的施體雜質為Ge，且具有小於0.03 Ω･cm的室溫電阻率，以及（004）XRD搖擺曲線FWHM小於20 arcsec。An n-type GaN crystal having a highest donor impurity concentration of Ge, a room temperature resistivity of less than 0.03 Ω･cm, and a (004) XRD swing curve FWHM of less than 20 arcsec.一種n型GaN結晶，其係如申請專利範圍第1項之n型GaN結晶，其中該結晶具有互相朝向相反方向的2個主面，該2個主面的面積分別為3 cm²以上，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下。An n-type GaN crystal, which is the n-type GaN crystal as claimed in claim 1, wherein the crystal has two main surfaces facing opposite directions, the areas of the two main surfaces are respectively greater than 3^cm2 , and one of the two main surfaces is Ga-polar and has an inclination of greater than 0 degrees and less than 10 degrees relative to a (0001) crystal plane.如申請專利範圍第2項之n型GaN結晶，其具有20mm以上的直徑。For example, the n-type GaN crystal in item 2 of the patent application has a diameter of more than 20 mm.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 其所含有之最高濃度的施體雜質為Ge； 且具有小於0.03 Ω･cm的室溫電阻率；及 在該一側的主面上沿著至少1條線於長度40mm中每隔1mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to the (0001) crystal plane, containing Ge as the highest concentration of donor impurities; and having a room temperature resistivity of less than 0.03 Ω･cm; and when the (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 其所含有之最高濃度的施體雜質為Ge； 且具有小於0.03 Ω･cm的室溫電阻率；及 在該一側的主面上沿著至少1條線於長度40mm中每隔1mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18 arcsec以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to the (0001) crystal plane, containing Ge as the highest concentration of donor impurities; and having a room temperature resistivity of less than 0.03 Ω･cm; and when the (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the average value of the FWHM of the (004) XRD swing curve between all measurement points is less than 18 arcsec.如申請專利範圍第4項之n型GaN結晶，其中該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, in the n-type GaN crystal of claim 4, the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 其所含有之最高濃度的施體雜質為Ge； 且具有小於0.03 Ω･cm的室溫電阻率；及 在該一側的主面上分別沿著至少2條互相垂直的線於長度40mm中每隔1mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to the (0001) crystal plane, containing Ge as the highest concentration of donor impurities; and having a room temperature resistivity of less than 0.03 Ω･cm; and when the (004) XRD swing curve is measured along at least two mutually perpendicular lines at intervals of 1 mm in a length of 40 mm on the main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 其所含有之最高濃度的施體雜質為Ge； 且具有小於0.03 Ω･cm的室溫電阻率；及 在該一側的主面上分別沿著至少2條互相垂直的線於長度40mm中每隔1mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18 arcsec以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to the (0001) crystal plane, containing Ge as the highest concentration of donor impurities; and having a room temperature resistivity of less than 0.03 Ω･cm; and when the (004) XRD swing curve is measured along at least two mutually perpendicular lines at intervals of 1 mm in a length of 40 mm on the main surface on one side, the average value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 18 arcsec.如申請專利範圍第7項之n型GaN結晶，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, in the n-type GaN crystal of claim 7, the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第2至9項中任一項之n型GaN結晶，其具有小於0.02 Ω･cm的室溫電阻率。An n-type GaN crystal according to any one of items 2 to 9 of the patent application has a room temperature resistivity of less than 0.02 Ω･cm.如申請專利範圍第2至9項中任一項之n型GaN結晶，其載子濃度為1×10¹⁸cm^-3以上。For an n-type GaN crystal according to any one of items 2 to 9 of the patent application, the carrier concentration is greater than 1×10¹⁸ cm^-3 .如申請專利範圍第2至7項中任一項之n型GaN結晶，其中關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal according to any one of items 2 to 7 of the patent application, wherein the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第12項之n型GaN結晶，其滿足與雜質濃度相關的條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。For example, the n-type GaN crystal of claim 12 satisfies condition (a) related to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第2至9項中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下。An n-type GaN crystal according to any one of items 2 to 9 of the patent application, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第2至9項中任一項之n型GaN結晶，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。An n-type GaN crystal according to any one of claims 2 to 9, wherein the Ge concentration is greater than 1×10¹⁸ atoms/cm³ and the Si concentration is greater than 4×10¹⁷ atoms/cm³ .如申請專利範圍第2至9項中任一項之n型GaN結晶，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。In the n-type GaN crystal of any one of claims 2 to 9, the concentration of each impurity except Ge, Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第2至9項中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。The n-type GaN crystal of any one of items 2 to 9 of the patent application scope is a GaN crystal grown by HVPE.一種GaN晶圓，其係由如申請專利範圍第2至17項中任一項之n型GaN結晶所構成。A GaN wafer is composed of an n-type GaN crystal as claimed in any one of claims 2 to 17.一種GaN晶圓，其Ga極性側設有如申請專利範圍第2至17項中任一項之n型GaN結晶所構成的第一區域，而N極性側則設有載子濃度低於該n型GaN結晶的第二區域。A GaN wafer has a first region on its Ga polarity side that is composed of an n-type GaN crystal as in any one of claims 2 to 17, and a second region on its N polarity side that has a carrier concentration lower than that of the n-type GaN crystal.如申請專利範圍第19項之GaN晶圓，其中該第一區域的厚度為5 μm以上250 μm以下。For example, in the GaN wafer of item 19 of the patent application, the thickness of the first region is greater than 5 μm and less than 250 μm.如申請專利範圍第19項之GaN晶圓，其中該第二區域，關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。In the GaN wafer of claim 19, the second region satisfies the following condition (c) regarding impurity concentration: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第21項之GaN晶圓，其中該第二區域滿足與雜質濃度相關的條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。For example, in the GaN wafer of claim 21, the second region satisfies condition (a) related to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第19至22項中任一項之GaN晶圓，其中該第二區域中的O濃度為3×10¹⁶atoms/cm³以下。In the GaN wafer of any one of claims 19 to 22, the O concentration in the second region is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第19至22項中任一項之GaN晶圓，其中該第二區域中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。In the GaN wafer of any one of claims 19 to 22, the concentration of each impurity in the second region, except for Si, O and H, is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第19至22項中任一項之GaN晶圓，其中該第一區域與該第二區域之間具有再成長界面。A GaN wafer as claimed in any one of items 19 to 22 of the patent application, wherein a re-growth interface is provided between the first region and the second region.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第18至25項中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a GaN wafer as described in any one of items 18 to 25 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種磊晶晶圓，其係由如申請專利範圍第18至25項中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer is composed of a GaN wafer as defined in any one of claims 18 to 25 and one or more nitride semiconductor layers epitaxially grown on the GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第18至25項中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a GaN wafer as described in any one of items 18 to 25 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種n型GaN結晶，其具有小於0.03 Ω･cm的室溫電阻率，且（004）XRD搖擺曲線FWHM小於20 arcsec，而關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having a room temperature resistivity of less than 0.03 Ω･cm and a (004) XRD swing curve FWHM of less than 20 arcsec, and satisfying the following (c) condition with respect to impurity concentration: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係如申請專利範圍第29項之n型GaN結晶，該結晶具有互相朝向相反方向的2個主面，該2個主面的面積分別為3 cm²以上，該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下。An n-type GaN crystal, which is the n-type GaN crystal of claim 29, wherein the crystal has two main surfaces facing opposite directions, the areas of the two main surfaces are respectively greater than 3^cm2 , and one of the two main surfaces is Ga-polar and has an inclination of greater than 0 degrees and less than 10 degrees relative to a (0001) crystal plane.如申請專利範圍第30項之n型GaN結晶，其具有20mm以上的直徑。For example, the n-type GaN crystal of item 30 of the patent application has a diameter of more than 20 mm.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 具有小於0.03 Ω･cm的室溫電阻率； 在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度，滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm; when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec; and regarding impurity concentration, the following condition (c) is satisfied: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 具有小於0.03 Ω･cm的室溫電阻率； 在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18 arcsec以下；及 關於雜質濃度，滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm; when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the average value of the FWHM of the (004) XRD swing curve between all measurement points is less than 18 arcsec; and regarding impurity concentration, the following condition (c) is satisfied: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第32項之n型GaN結晶，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the n-type GaN crystal of claim 32, wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 具有小於0.03 Ω･cm的室溫電阻率； 在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為 20 arcsec以下；及 關於雜質濃度，滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm; when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the main surface at intervals of 1 mm over a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec; and regarding impurity concentration, the following condition (c) is satisfied: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 具有小於0.03 Ω･cm的室溫電阻率； 在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18  arcsec以下；及 關於雜質濃度，滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of 0 to 10 degrees relative to a (0001) crystal plane, having a room temperature resistivity of less than 0.03 Ω･cm; when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the main surface at intervals of 1 mm over a length of 40 mm, the average value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 18 arcsec; and regarding impurity concentration, the following condition (c) is satisfied: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第35項之n型GaN結晶，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the n-type GaN crystal of claim 35, wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第30至37項中任一項之n型GaN結晶，其具有小於0.02 Ω･cm的室溫電阻率。An n-type GaN crystal according to any one of claims 30 to 37, having a room temperature resistivity of less than 0.02 Ω･cm.如申請專利範圍第30至37項中任一項之n型GaN結晶，其載子濃度為1×10¹⁸cm^-3以上。For an n-type GaN crystal according to any one of items 30 to 37 of the patent application, the carrier concentration is greater than 1×10¹⁸ cm^-3 .如申請專利範圍第30至37項中任一項之n型GaN結晶，其中關於雜質濃度滿足下述條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。An n-type GaN crystal according to any one of items 30 to 37 of the patent application, wherein the impurity concentration satisfies the following condition (a): (a) the Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第30至37項中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下。An n-type GaN crystal according to any one of items 30 to 37 of the patent application, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第30至37項中任一項之n型GaN結晶，其所含有之最高濃度的施體雜質為Si。For an n-type GaN crystal of any one of claims 30 to 37, the highest concentration of the donor impurity contained therein is Si.如申請專利範圍第42項之n型GaN結晶，其中Si以外之施體雜質的總濃度為Si濃度的10%以下。For example, in the n-type GaN crystal of claim 42, the total concentration of donor impurities other than Si is less than 10% of the Si concentration.如申請專利範圍第43項之n型GaN結晶，其中載子濃度為Si濃度的90%以上。For example, in the n-type GaN crystal of claim 43, the carrier concentration is more than 90% of the Si concentration.如申請專利範圍第30至37項中任一項之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For an n-type GaN crystal according to any one of claims 30 to 37, the concentration of each impurity except Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第30至37項中任一項之n型GaN結晶，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。For an n-type GaN crystal according to any one of claims 30 to 37, wherein the Ge concentration is greater than 1×10¹⁸ atoms/cm³ and the Si concentration is greater than 4×10¹⁷ atoms/cm³ .如申請專利範圍第46項之n型GaN結晶，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For example, in the n-type GaN crystal of claim 46, except for Ge, Si, O and H, the concentration of each impurity is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第30至37項中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。The n-type GaN crystal of any one of claims 30 to 37 is a GaN crystal grown by HVPE.一種GaN晶圓，其係由如申請專利範圍第30至48項中任一項之n型GaN結晶所構成。A GaN wafer is composed of an n-type GaN crystal as claimed in any one of claims 30 to 48.一種GaN晶圓，其Ga極性側設有如申請專利範圍第30至48項中任一項之n型GaN結晶所構成的第一區域，而N極性側設有載子濃度低於該n型GaN結晶的第二區域。A GaN wafer has a first region on its Ga polarity side that is composed of an n-type GaN crystal as in any one of claims 30 to 48, and a second region on its N polarity side that has a carrier concentration lower than that of the n-type GaN crystal.如申請專利範圍第50項之GaN晶圓，其中該第一區域的厚度為5 μm以上250 μm以下。For example, in the GaN wafer of item 50 of the patent application, the thickness of the first region is greater than 5 μm and less than 250 μm.如申請專利範圍第50項之GaN晶圓，其中該第二區域，關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。For example, in the GaN wafer of claim 50, the second region satisfies the following condition (c) regarding impurity concentration: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第52項之GaN晶圓，其中該第二區域滿足與雜質濃度相關的條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。For example, in the GaN wafer of claim 52, the second region satisfies condition (a) related to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第50至53項中任一項之GaN晶圓，其中該第二區域中的O濃度為3×10¹⁶atoms/cm³以下。In the GaN wafer of any one of claims 50 to 53, the O concentration in the second region is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第50至53項中任一項之GaN晶圓，其中該第二區域中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。In the GaN wafer of any one of claims 50 to 53, in the second region, except for Si, O and H, the concentration of each impurity is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第50至53項中任一項之GaN晶圓，其中該第一區域與該第二區域之間具有再成長界面。A GaN wafer as claimed in any one of items 50 to 53 of the patent application, wherein a re-growth interface is provided between the first region and the second region.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第49至56項中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a GaN wafer as described in any one of items 49 to 56 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種磊晶晶圓，其係由如申請專利範圍第49至56項中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer is composed of a GaN wafer as in any one of items 49 to 56 of the patent application range and one or more nitride semiconductor layers epitaxially grown on the GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第49至56項中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a GaN wafer as described in any one of items 49 to 56 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 具有45 mm以上的直徑； （004）XRD搖擺曲線FWHM小於20 arcsec，以及關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main faces facing opposite directions, one of the two main faces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees relative to a (0001) crystal plane, having a diameter of not less than 45 mm; a (004) XRD wobble curve FWHM of less than 20 arcsec, and satisfying the following condition (c) regarding impurity concentration: (c) H concentration is not more than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is not more than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is not more than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 在該一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main surfaces facing opposite directions, one of the two main surfaces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface on one side, the average value of the FWHM of the (004) XRD swing curve between all measurement points is not more than 18 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is not more than 1×10¹⁷ atoms/cm³ .如申請專利範圍第61項之n型GaN結晶，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the n-type GaN crystal of claim 61, wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main faces facing opposite directions, one of the two main faces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the main face on one side at intervals of 1 mm in a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is not more than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is not more than 1×10¹⁷ atoms/cm³ .一種n型GaN結晶，其係具有互相朝向相反方向的2個主面、該2個主面中的一面為Ga極性且相對於（0001）結晶面的傾斜在0度以上10度以下的n型GaN結晶， 在該一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值為18 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。An n-type GaN crystal having two main faces facing in opposite directions, one of the two main faces being Ga-polar and having an inclination of not less than 0 degrees and not more than 10 degrees with respect to a (0001) crystal plane, wherein when a (004) XRD swing curve is measured along at least two mutually perpendicular lines on the main face on one side at intervals of 1 mm in a length of 40 mm, the average value of the FWHM of the (004) XRD swing curve between all measurement points on each line is not more than 18 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is not more than 1×10¹⁷ atoms/cm³ .如申請專利範圍第64項之n型GaN結晶，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the n-type GaN crystal of claim 64, wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第60至64項中任一項之n型GaN結晶，其中關於雜質濃度滿足條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。An n-type GaN crystal as claimed in any one of items 60 to 64 of the patent application, wherein the impurity concentration satisfies condition (a): (a) the Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第60至66項中任一項之n型GaN結晶，其中Si濃度為5×10¹⁷atoms/cm³以下。An n-type GaN crystal according to any one of claims 60 to 66, wherein the Si concentration is less than 5×10¹⁷ atoms/cm³ .如申請專利範圍第60至66項中任一項之n型GaN結晶，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For an n-type GaN crystal according to any one of claims 60 to 66, the concentration of each impurity except Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第60至66項中任一項之n型GaN結晶，其中O濃度為3×10¹⁶atoms/cm³以下。An n-type GaN crystal according to any one of items 60 to 66 of the patent application, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第60至66項中任一項之n型GaN結晶，其具有小於5×10¹⁷cm^-3的載子濃度與0.04 Ω･cm以上的室溫電阻率中的至少任一者。The n-type GaN crystal of any one of claims 60 to 66 has at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of not less than 0.04 Ω･cm.如申請專利範圍第60至66項中任一項之n型GaN結晶，其係以HVPE成長的GaN結晶。An n-type GaN crystal as claimed in any one of claims 60 to 66, which is a GaN crystal grown by HVPE.一種GaN晶圓，其係由如申請專利範圍第60至72項中任一項之n型GaN結晶所構成。A GaN wafer is composed of an n-type GaN crystal as described in any one of claims 60 to 72.一種雙層GaN晶圓，具有：底層，其係由如申請專利範圍第60至72項中任一項之n型GaN結晶所構成；及表層，其係由GaN所構成，隔著再成長界面而形成於該n型GaN結晶的Ga極性側的主面上，且最小厚度為20 μm以上；在該表層中，從頂面至少距離5 μm以內的部分包含於高載子濃度區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域。A double-layer GaN wafer comprises: a bottom layer, which is composed of an n-type GaN crystal as in any one of items 60 to 72 of the patent application scope; and a surface layer, which is composed of GaN and is formed on the main surface of the Ga polar side of the n-type GaN crystal across a re-growth interface, and has a minimum thickness of 20 μm or more; in the surface layer, a portion at least 5 μm away from the top surface is included in a high carrier concentration region, and the high carrier concentration region is a region with a carrier concentration lower limit of 1×10¹⁸ cm^-3 or more.如申請專利範圍第74項之雙層GaN晶圓，其中在該表層中，從頂面至少20 μm以內的部分包含於該高載子濃度區域。For example, in the double-layer GaN wafer of claim 74, a portion of the surface layer at least within 20 μm from the top surface is included in the high carrier concentration region.如申請專利範圍第74項之雙層GaN晶圓，其中該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上的區域。For example, in the double-layer GaN wafer of claim 74, the high carrier concentration region is a region where the lower limit of the carrier concentration is greater than 2×10¹⁸ cm^-3 .如申請專利範圍第74項之雙層GaN晶圓，其中該表層，關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。For example, in the double-layer GaN wafer of claim 74, the surface layer satisfies the following condition (c) regarding impurity concentration: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第77項之雙層GaN晶圓，其中該表層滿足與雜質濃度相關的條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。For example, in the double-layer GaN wafer of claim 77, the surface layer satisfies condition (a) related to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該表層中的O濃度為3×10¹⁶atoms/cm³以下。A double-layer GaN wafer as claimed in any one of claims 74 to 78, wherein the O concentration in the surface layer is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該高載子濃度區域摻雜有Si。A double-layer GaN wafer as claimed in any one of claims 74 to 78, wherein the high carrier concentration region is doped with Si.如申請專利範圍第80項之雙層GaN晶圓，其中該表層中，除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For example, in the double-layer GaN wafer of claim 80, the concentration of each impurity in the surface layer, except for Si, O and H, is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該高載子濃度區域摻雜有Ge。A double-layer GaN wafer as claimed in any one of claims 74 to 78, wherein the high carrier concentration region is doped with Ge.如申請專利範圍第82項之雙層GaN晶圓，其中該表層中，除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For example, in the double-layer GaN wafer of claim 82, the concentration of each impurity in the surface layer, except for Ge, Si, O and H, is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該高載子濃度區域中，載子濃度或施體雜質的總濃度沿著c軸方向的變動，相較於中間值，係在±25%以內。A double-layer GaN wafer as claimed in any one of claims 74 to 78, wherein in the high carrier concentration region, a variation of the carrier concentration or the total concentration of donor impurities along the c-axis direction is within ±25% relative to the median value.一種雙層GaN晶圓，具有：底層，其係由如申請專利範圍第60至72項中任一項之n型GaN結晶所構成；及表層，其係由GaN所構成，隔著再成長界面而形成於該n型GaN結晶的Ga極性側的主面上，且最小厚度為20 μm以上；在該表層中，從頂面至少距離5 μm以內的部分包含於載子補償區域，該載子補償區域係補償雜質的總濃度下限為1×10¹⁷atoms/cm³以上的區域。A double-layer GaN wafer comprises: a bottom layer, which is composed of an n-type GaN crystal as in any one of items 60 to 72 of the patent application scope; and a surface layer, which is composed of GaN and is formed on the main surface of the Ga polar side of the n-type GaN crystal across a re-growth interface, and has a minimum thickness of 20 μm or more; in the surface layer, a portion at least 5 μm away from the top surface is included in a carrier compensation region, and the carrier compensation region is a region where the lower limit of the total concentration of compensation impurities is 1×10¹⁷ atoms/cm³ or more.如申請專利範圍第85項之雙層GaN晶圓，其中在該表層中，從頂面至少20 μm以內的部分包含於該載子補償區域。For example, in the double-layer GaN wafer of claim 85, a portion of the surface layer at least within 20 μm from the top surface is included in the carrier compensation region.如申請專利範圍第85項之雙層GaN晶圓，其中該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。For example, in the double-layer GaN wafer of claim 85, the carrier compensation region is a region where the lower limit of the total concentration of the compensation impurities is greater than 2×10¹⁷ atoms/cm³ .如申請專利範圍第85至87項中任一項之雙層GaN晶圓，其中該表層，關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A double-layer GaN wafer as claimed in any one of items 85 to 87 of the patent application, wherein the surface layer satisfies the following condition (c) regarding impurity concentration: (c) H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第85至87項中任一項之雙層GaN晶圓，其中該載子補償區域中，補償雜質的總濃度沿著c軸方向的變動，相較於中間值，係在±25%以內。For a double-layer GaN wafer as claimed in any one of claims 85 to 87, wherein the variation of the total concentration of the compensation impurities in the carrier compensation region along the c-axis direction is within ±25% compared to the median value.如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該雙層GaN晶圓的厚度大於300 μm，該表層的最大厚度在300 μm以下。For a double-layer GaN wafer as claimed in any one of items 74 to 78 of the patent application, the thickness of the double-layer GaN wafer is greater than 300 μm, and the maximum thickness of the surface layer is less than 300 μm.如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該表層的最小厚度在50 μm以上。A double-layer GaN wafer as claimed in any one of items 74 to 78 of the patent application, wherein the minimum thickness of the surface layer is greater than 50 μm.如申請專利範圍第74至78項中任一項之雙層GaN晶圓，其中該表層的最大厚度與最小厚度的差在200 μm以下。For a double-layer GaN wafer as claimed in any one of items 74 to 78 of the patent application, the difference between the maximum thickness and the minimum thickness of the surface layer is less than 200 μm.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第73至92項中任一項之晶圓的步驟；及在該所準備之晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a wafer as described in any one of items 73 to 92 of the patent application; and epitaxially growing one or more nitride semiconductor layers on the prepared wafer.一種磊晶晶圓，其係由如申請專利範圍第73至92項中任一項之晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer, which is composed of a wafer as in any one of items 73 to 92 of the patent application range and one or more nitride semiconductor layers epitaxially grown on the GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第73至92項中任一項之晶圓的步驟；及在該所準備之晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a wafer as described in any one of items 73 to 92 of the patent application; and epitaxially growing one or more nitride semiconductor layers on the prepared wafer.一種雙層GaN晶圓的製造方法，具有：準備如申請專利範圍第73項之GaN晶圓的步驟；及在該所準備之GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。A method for manufacturing a double-layer GaN wafer comprises: a step of preparing a GaN wafer as described in item 73 of the patent application; and a step of epitaxially growing a GaN layer having a thickness of more than 20 μm on the main surface of the Ga polar side of the prepared GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region having a carrier concentration lower limit of more than 1×10¹⁸ cm^-3 , and the carrier compensation region is a region having a total concentration lower limit of compensation impurities of more than 2×10¹⁷ atoms/cm³ .如申請專利範圍第96項之製造方法，其中在該磊晶成長之步驟中，係以HVPE使該GaN層成長。As in the manufacturing method of item 96 of the patent application scope, in the step of epitaxial growth, the GaN layer is grown by HVPE.如申請專利範圍第96項之製造方法，其中該GaN層的厚度為500 μm以下。As in the manufacturing method of item 96 of the patent application scope, the thickness of the GaN layer is less than 500 μm.如申請專利範圍第96至98項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上的區域。In the manufacturing method of any one of items 96 to 98 of the patent application, the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region with a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more.如申請專利範圍第96至98項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。In the manufacturing method of any one of items 96 to 98 of the patent application scope, the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge.如申請專利範圍第96至98項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意地摻雜有Si。In the manufacturing method of any one of items 96 to 98 of the patent application scope, the high carrier concentration region is provided on the GaN layer, and Si is intentionally doped in the high carrier concentration region.如申請專利範圍第96至98項中任一項之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域，係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上的區域。In the manufacturing method of any one of items 96 to 98 of the patent application, the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the compensation impurities in the carrier compensation region is greater than 5×10¹⁷ atoms/cm³ .如申請專利範圍第96至98項中任一項之製造方法，其中更具有：將該磊晶成長之步驟中所得到的積層體薄化的步驟。The manufacturing method of any one of items 96 to 98 of the patent application scope further comprises: a step of thinning the multilayer body obtained in the epitaxial growth step.一種塊體GaN結晶的製造方法，具有：準備如申請專利範圍第73項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使GaN磊晶成長的步驟。A method for manufacturing bulk GaN crystals comprises: a step of preparing a GaN wafer as described in item 73 of the patent application; and a step of epitaxially growing GaN on the prepared GaN wafer.一種c面GaN晶圓： 其所含有之最高濃度的施體雜質為Ge； 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率；及 （004）XRD搖擺曲線FWHM小於20 arcsec。A c-plane GaN wafer:The highest concentration of donor impurities contained therein is Ge;The conductivity type is n-type and has a room temperature resistivity of less than 0.03 Ω･cm; andThe (004) XRD swing curve FWHM is less than 20 arcsec.如申請專利範圍第105項之c面GaN晶圓，其具備面積3 cm²以上的主面。For example, the c-plane GaN wafer of claim 105 has a main surface with an area of more than 3^cm2 .如申請專利範圍第105項之c面GaN晶圓，其具有20 mm以上的直徑。For example, the c-plane GaN wafer of item 105 of the patent application has a diameter of more than 20 mm.一種c面GaN晶圓： 其所含有之最高濃度的施體雜質為Ge； 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率；及 在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。A c-plane GaN wafer:The highest concentration of donor impurities contained therein is Ge;The conductivity type is n-type and has a room temperature resistivity of less than 0.03 Ω･cm; andWhen the (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on the main surface of one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec.如申請專利範圍第108項之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the c-plane GaN wafer of claim 108, wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種c面GaN晶圓： 其所含有之最高濃度的施體雜質為Ge； 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率；及 在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下。A c-plane GaN wafer:The highest concentration of donor impurities contained therein is Ge;The conductivity type is n-type and has a room temperature resistivity of less than 0.03 Ω･cm; andWhen the (004) XRD swing curve is measured at intervals of 1 mm along at least two mutually perpendicular lines on a main surface of one side at a length of 40 mm, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec.如申請專利範圍第110項之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, in the c-plane GaN wafer of claim 110, wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下。For a c-plane GaN wafer as claimed in any one of items 105 to 111 of the patent application, the variation amplitude of the x-direction component of the cutting angle on a line extending in the x-direction through the center of the surface and the variation amplitude of the y-direction component of the cutting angle on a line extending in the y-direction perpendicular to the x-direction through the center of the surface are respectively less than 0.15 degrees within a length range of 40 mm.如申請專利範圍第105至111項中任一項之c面GaN晶圓，其具有小於0.02 Ω･cm的室溫電阻率。A c-plane GaN wafer according to any one of claims 105 to 111, having a room temperature resistivity of less than 0.02 Ω･cm.如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中載子濃度為1×10¹⁸cm^-3以上。A c-plane GaN wafer as claimed in any one of items 105 to 111, wherein the carrier concentration is greater than 1×10¹⁸ cm^-3 .如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer as claimed in any one of items 105 to 111 of the patent application, wherein the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第115項之c面GaN晶圓，其滿足與雜質濃度相關的條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。For example, the c-plane GaN wafer of claim 115 satisfies condition (a) related to impurity concentration: (a) Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下。A c-plane GaN wafer as claimed in any one of claims 105 to 111, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中Ge濃度為1×10¹⁸atoms/cm³以上，且Si濃度為4×10¹⁷atoms/cm³以上。A c-plane GaN wafer as claimed in any one of claims 105 to 111, wherein the Ge concentration is greater than 1×10¹⁸ atoms/cm³ and the Si concentration is greater than 4×10¹⁷ atoms/cm³ .如申請專利範圍第105至111項中任一項之c面GaN晶圓，其中除了Ge、Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For a c-plane GaN wafer as claimed in any one of claims 105 to 111, the concentration of each impurity except Ge, Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第105至111項中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。A c-plane GaN wafer as claimed in any one of claims 105 to 111, wherein the c-plane GaN wafer is composed of GaN crystals grown by HVPE.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第105至120項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a c-plane GaN wafer as described in any one of items 105 to 120 of the patent application; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer.一種磊晶晶圓，其係由如申請專利範圍第105至120項中任一項之GaN晶圓與在該GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer is composed of a GaN wafer as in any one of items 105 to 120 of the patent application range and one or more nitride semiconductor layers epitaxially grown on the GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第105至120項中任一項之GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a GaN wafer as described in any one of items 105 to 120 of the patent application; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種c面GaN晶圓： 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率； （004）XRD搖擺曲線FWHM小於20 arcsec；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity and a room temperature resistivity of less than 0.03 Ω･cm; having a (004) XRD swing curve FWHM of less than 20 arcsec; and having an impurity concentration satisfying the following (c): (c) a H concentration of less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第124項之c面GaN晶圓，其具備面積3 cm²以上的主面。For example, the c-plane GaN wafer of claim 124 has a main surface with an area of more than 3^cm2 .如申請專利範圍第124項之c面GaN晶圓，其具有20 mm以上的直徑。For example, the c-plane GaN wafer of item 124 of the patent application has a diameter of more than 20 mm.一種c面GaN晶圓： 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率； 在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity and a room temperature resistivity of less than 0.03 Ω･cm; when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on a main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第127項之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the c-plane GaN wafer of claim 127, wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種c面GaN晶圓： 導電型為n型、且具有小於0.03 Ω･cm的室溫電阻率； 在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity and a room temperature resistivity of less than 0.03 Ω･cm; when the (004) XRD swing curve is measured along at least two mutually perpendicular lines at intervals of 1 mm in a length of 40 mm on a main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第129項之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the c-plane GaN wafer of claim 129, wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第124至130項中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下。For a c-plane GaN wafer as claimed in any one of items 124 to 130 of the patent application, the variation amplitude of the x-direction component of the cutting angle on a line extending in the x-direction through the center of the surface and the variation amplitude of the y-direction component of the cutting angle on a line extending in the y-direction perpendicular to the x-direction through the center of the surface are respectively less than 0.15 degrees within a length range of 40 mm.如申請專利範圍第124至130項中任一項之c面GaN晶圓，其具有小於0.02 Ω･cm的室溫電阻率。A c-plane GaN wafer according to any one of claims 124 to 130, having a room temperature resistivity of less than 0.02 Ω･cm.如申請專利範圍第124至130項中任一項之c面GaN晶圓，其載子濃度為1×10¹⁸cm^-3以上。For a c-plane GaN wafer according to any one of items 124 to 130 of the patent application, the carrier concentration is greater than 1×10¹⁸ cm^-3 .如申請專利範圍第124至130項中任一項之c面GaN晶圓，其中關於雜質濃度滿足條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。A c-plane GaN wafer as claimed in any one of items 124 to 130, wherein the impurity concentration satisfies condition (a): (a) the Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第124至130項中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下。A c-plane GaN wafer according to any one of claims 124 to 130, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第124至130項中任一項之c面GaN晶圓，其所含有之最高濃度的施體雜質為Si。For a c-plane GaN wafer as claimed in any one of claims 124 to 130, the highest concentration of the donor impurity contained therein is Si.如申請專利範圍第136項之c面GaN晶圓，其中Si以外之施體雜質的總濃度為Si濃度的10%以下。For example, in the c-plane GaN wafer of claim 136, the total concentration of donor impurities other than Si is less than 10% of the Si concentration.如申請專利範圍第137項之c面GaN晶圓，其中載子濃度為Si濃度的90%以上。For example, in the c-plane GaN wafer of claim 137, the carrier concentration is more than 90% of the Si concentration.如申請專利範圍第124至130項中任一項之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For a c-plane GaN wafer as claimed in any one of claims 124 to 130, the concentration of each impurity except Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第124至130項中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。A c-plane GaN wafer as claimed in any one of claims 124 to 130, which is composed of GaN crystals grown by HVPE.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第124至140項中任一項之c面GaN晶圓的步驟；及在該所準備之GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a c-plane GaN wafer as described in any one of items 124 to 140 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared GaN wafer.一種磊晶晶圓，其係由如申請專利範圍第124至140項中任一項之c面GaN晶圓與在該c面GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer is composed of a c-plane GaN wafer as in any one of items 124 to 140 of the patent application range and one or more nitride semiconductor layers epitaxially grown on the c-plane GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第124至140項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a c-plane GaN wafer as described in any one of items 124 to 140 of the patent application; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer.一種c面GaN晶圓： 導電型為n型； 具有45mm以上的直徑； （004）XRD搖擺曲線FWHM小於20 arcsec；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity; having a diameter of 45 mm or more; having a (004) XRD wobble curve FWHM of less than 20 arcsec; and having an impurity concentration satisfying the following condition (c): (c) a H concentration of less than 1×10¹⁷ atoms/cm³ .一種c面GaN晶圓： 導電型為n型； 在一側的主面上沿著至少1條線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在所有測量點之間，（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity; when a (004) XRD swing curve is measured at intervals of 1 mm along at least one line in a length of 40 mm on a main surface on one side, the maximum value of the FWHM of the (004) XRD swing curve between all measurement points is less than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第145項之c面GaN晶圓，其中在該所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the c-plane GaN wafer of claim 145, wherein the average value of the FWHM of the (004) XRD swing curve among all the measurement points is less than 18 arcsec.一種c面GaN晶圓： 導電型為n型； 在一側的主面上分別沿著至少2條互相垂直的線於長度40 mm中每隔1 mm即測量（004）XRD搖擺曲線時，在各線上的所有測量點之間；（004）XRD搖擺曲線FWHM的最大值為20 arcsec以下；及 關於雜質濃度滿足下述（c）的條件： （c）H濃度為1×10¹⁷atoms/cm³以下。A c-plane GaN wafer: having an n-type conductivity; measuring a (004) XRD swing curve along at least two mutually perpendicular lines at intervals of 1 mm in a length of 40 mm on a main surface on one side; the maximum value of the FWHM of the (004) XRD swing curve between all measurement points on each line is less than 20 arcsec; and the impurity concentration satisfies the following condition (c): (c) the H concentration is less than 1×10¹⁷ atoms/cm³ .如申請專利範圍第147項之c面GaN晶圓，其中在該各線上的所有測量點之間，（004）XRD搖擺曲線FWHM的平均值在18 arcsec以下。For example, the c-plane GaN wafer of claim 147, wherein the average value of the FWHM of the (004) XRD swing curve between all measurement points on the lines is less than 18 arcsec.如申請專利範圍第144至148項中任一項之c面GaN晶圓，其中切割角之x方向分量在通過表面中心而在x方向上延伸之線的變動幅度與切割角之y方向分量在通過表面中心而在與該x方向垂直的y方向上延伸之線上的變動幅度，在長度40 mm的區間內分別為0.15度以下。For a c-plane GaN wafer as claimed in any one of items 144 to 148 of the patent application, the variation amplitude of the x-direction component of the cutting angle on a line extending in the x-direction through the center of the surface and the variation amplitude of the y-direction component of the cutting angle on a line extending in the y-direction perpendicular to the x-direction through the center of the surface are respectively less than 0.15 degrees within a length range of 40 mm.如申請專利範圍第144至148項中任一項之c面GaN晶圓，其中關於雜質濃度滿足條件（a）： （a）Si濃度為5×10¹⁶atoms/cm³以上。A c-plane GaN wafer as claimed in any one of items 144 to 148 of the patent application, wherein the impurity concentration satisfies condition (a): (a) the Si concentration is greater than 5×10¹⁶ atoms/cm³ .如申請專利範圍第144至148項中任一項之c面GaN晶圓，其中Si濃度為5×10¹⁷atoms/cm³以下。A c-plane GaN wafer as claimed in any one of claims 144 to 148, wherein the Si concentration is less than 5×10¹⁷ atoms/cm³ .如申請專利範圍第144至148項中任一項之c面GaN晶圓，其中除了Si、O及H以外，各雜質的濃度為5×10¹⁵atoms/cm³以下。For a c-plane GaN wafer as claimed in any one of claims 144 to 148, the concentration of each impurity except Si, O and H is less than 5×10¹⁵ atoms/cm³ .如申請專利範圍第144至148項中任一項之c面GaN晶圓，其中O濃度為3×10¹⁶atoms/cm³以下。A c-plane GaN wafer as claimed in any one of claims 144 to 148, wherein the O concentration is less than 3×10¹⁶ atoms/cm³ .如申請專利範圍第144至148項中任一項之c面GaN晶圓，其具有小於5×10¹⁷cm^-3的載子濃度與0.04 Ω･cm以上的室溫電阻率中的至少任一者。A c-plane GaN wafer as claimed in any one of claims 144 to 148, having at least one of a carrier concentration of less than 5×10¹⁷ cm^-3 and a room temperature resistivity of greater than 0.04 Ω･cm.如申請專利範圍第144至148項中任一項之c面GaN晶圓，其係由以HVPE成長的GaN結晶所構成。A c-plane GaN wafer as claimed in any one of claims 144 to 148, wherein the c-plane GaN wafer is composed of GaN crystals grown by HVPE.一種磊晶晶圓的製造方法，其係由下述步驟所構成：準備如申請專利範圍第144至155項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing an epitaxial wafer comprises the following steps: preparing a c-plane GaN wafer as described in any one of items 144 to 155 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer.一種磊晶晶圓，其係由如申請專利範圍第144至155項中任一項之c面GaN晶圓與在該c面GaN晶圓上磊晶成長的一層以上的氮化物半導體層所構成。An epitaxial wafer is composed of a c-plane GaN wafer as in any one of items 144 to 155 of the patent application scope and one or more nitride semiconductor layers epitaxially grown on the c-plane GaN wafer.一種氮化物半導體裝置的製造方法，其係由下述步驟所構成：準備如申請專利範圍第144至155項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使一層以上的氮化物半導體層磊晶成長的步驟。A method for manufacturing a nitride semiconductor device comprises the following steps: preparing a c-plane GaN wafer as described in any one of items 144 to 155 of the patent application scope; and epitaxially growing one or more nitride semiconductor layers on the prepared c-plane GaN wafer.一種雙層GaN晶圓的製造方法，具有：準備如申請專利範圍第144至155項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓的Ga極性側的主面上使厚度20 μm以上的GaN層磊晶成長的步驟；該GaN層上設有高載子濃度區域或載子補償區域，該高載子濃度區域係載子濃度下限為1×10¹⁸cm^-3以上的區域，該載子補償區域係補償雜質的總濃度下限為2×10¹⁷atoms/cm³以上的區域。A method for manufacturing a double-layer GaN wafer comprises: a step of preparing a c-plane GaN wafer as in any one of items 144 to 155 of the patent application scope; and a step of epitaxially growing a GaN layer with a thickness of more than 20 μm on the main surface of the Ga polar side of the prepared c-plane GaN wafer; a high carrier concentration region or a carrier compensation region is provided on the GaN layer, the high carrier concentration region is a region with a carrier concentration lower limit of more than 1×10¹⁸ cm^-3 , and the carrier compensation region is a region with a total concentration lower limit of compensation impurities of more than 2×10¹⁷ atoms/cm³ .如申請專利範圍第159項之製造方法，其中在該磊晶成長之步驟中，以HVPE使該GaN層成長。As in the manufacturing method of claim 159, in the epitaxial growth step, the GaN layer is grown by HVPE.如申請專利範圍第159項之製造方法，其中該GaN層的厚度為500 μm以下。As in the manufacturing method of patent application No. 159, the thickness of the GaN layer is less than 500 μm.如申請專利範圍第159至161項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域係載子濃度下限為2×10¹⁸cm^-3以上的區域。In the manufacturing method of any one of items 159 to 161 of the patent application scope, the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is a region with a carrier concentration lower limit of 2×10¹⁸ cm^-3 or more.如申請專利範圍第159至161項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中摻雜有Ge。In the manufacturing method of any one of items 159 to 161 of the patent application scope, the high carrier concentration region is provided on the GaN layer, and the high carrier concentration region is doped with Ge.如申請專利範圍第159至161項中任一項之製造方法，其中該GaN層上設有該高載子濃度區域，該高載子濃度區域中蓄意地摻雜有Si。In the manufacturing method of any one of claims 159 to 161, the high carrier concentration region is provided on the GaN layer, and Si is intentionally doped in the high carrier concentration region.如申請專利範圍第159至161項中任一項之製造方法，其中該GaN層上設有該載子補償區域，該載子補償區域，係補償雜質的總濃度下限為5×10¹⁷atoms/cm³以上的區域。In the manufacturing method of any one of claims 159 to 161, the carrier compensation region is provided on the GaN layer, and the total concentration lower limit of the compensation impurities in the carrier compensation region is greater than 5×10¹⁷ atoms/cm³ .如申請專利範圍第159至161項中任一項之製造方法，其中更具有：將該磊晶成長之步驟中所得到的積層體薄化的步驟。The manufacturing method of any one of the patent application items 159 to 161 further comprises: a step of thinning the multilayer body obtained in the epitaxial growth step.一種塊體GaN結晶的製造方法，具有：準備如申請專利範圍第144至155項中任一項之c面GaN晶圓的步驟；及在該所準備之c面GaN晶圓上使GaN磊晶成長的步驟。A method for manufacturing bulk GaN crystals comprises: preparing a c-plane GaN wafer as described in any one of items 144 to 155 of the patent application; and epitaxially growing GaN on the prepared c-plane GaN wafer.